Chapter Text
“No,” you said, your voice cutting through the cold like a blade. “I’m not taking your offer.” For a fleeting moment, there was nothing but stillness. The world seemed to hold its breath. Then, his smile twitched, just the barest flicker of movement at the corner of his lips, as though your defiance amused him more than it should have.
He stood there, still as stone, the shadows at his feet twisting languidly, like serpents waiting for their master's command. A soft chuckle escaped him, low and cold, rippling through the quiet.
“Disappointing,” the Shadowbringer mused,“ but not unexpected.” His dark eyes drifted over your shoulder, sweeping lazily across the monsters gathered behind you. His eyes only lingered for a moment, a single, disdainful glance, before his attention fell back to you. His amusement deepened, lighting up the cold depths of his eyes.
“So,” he continued, “this is it, then? The great army you’ve rallied to face me? These trembling, weak souls?” His smirk widened, sharp and cruel as another laugh escaped him, colder, darker this time. “Pathetic. It’s almost insulting.”
You held his stare, refusing to blink, refusing to flinch. His eyes gleamed with a twisted sort of happiness that you had seen before, as though he relished in the thought of tearing everything you cared about apart. The snowfall around you slowed to a near standstill, the flakes frozen midair, as your chest tightened, your jaw ticking.
“I’ve beaten you with less,” you snapped. Memories of a time long past, of a different battle fought under different skies, flickered through your mind. His smile faltered, just for a moment, the sharp edges of his expression softening into something darker, something far more dangerous.
“That was a long time ago, hero,” he said, his voice dripping with venom. The shadows around him coiled tighter, their movements more deliberate now, like predators preparing to strike. The very air around him seemed to thicken, growing heavier, and darker, as though every shadow was being pulled toward him.
The ground beneath his feet began to tremble as shadowy figures emerged from the depths, their grotesque forms writhing unnaturally. Some were small, skittering like insects with eyes that glowed an eerie white, while others were monstrous in size, towering over the landscape like twisted giants.
Hollow eyes glowed from within their deformed faces, and their bodies jerked with every step as if barely held together by the dark magic that birthed them.
“It won’t happen again,” he snarled. The monsters behind you stiffened, and you could practically taste their fear. But, this was a sight you had seen before, and you scoffed.
“We’ll see about that,” you murmured, slowly lifting your hands, feeling that familiar thrum of magic begin to stir within you.
You inhaled sharply, your chest heaving as the intensity of the energy built, each breath pulling in the icy air that only seemed to feed your magic more. Sweat slicked your brow despite the cold, your body trembling with the effort of containing the power that crackled at your fingertips.
The air around you shifted, biting and sharp, crackling with magic as it answered your call. A brilliant, icy blue light ignited in your eyes, the glow so fierce it reflected off the snow at your feet.
The snow stirred, first in small whirls, then in larger gusts as it rose to meet your will. You took a step forward, and the snow responded, swirling higher and higher until it whirled around you.
“You’re not the only one who can raise an army,” you growled through gritted teeth. The effort sent another shudder down your spine, your magic thickening in the air until the very town itself seemed to hum with energy.
The ground rumbled beneath you as the first giant clawed its way free from the snow, its form towering and bulky, like a massive ice golem forged from a glacier itself. Its body was wide and solid, armor-like plates of thick ice covering every inch of its hulking frame.
Every step it took rumbled through the ground, sending vibrations through the air as it groaned in a low, deep rumble.
But one giant wasn’t enough. Your magic tugged at you, demanding more, and soon another rose beside the first, identical in shape and size, clawing its way free from the swirling storm of snow and ice.
The monsters around you gasped, their wide eyes fixed on the towering ice giants that now loomed over the battlefield. Some of them recoiled, surprise rippling through the crowd, while others stood frozen in awe at the sheer power you had summoned. Papyrus, standing among them jaw fell open, his orange eyelights expanding.
His enthusiasm flickered for a moment as he glanced between the towering golems and the smaller, sleeker creatures beginning to take shape around you. Wolves, sharp and dangerous, rose from the swirling snow, their bodies were first blobs of water before solidifying into jagged, crystalline armor.
Their eyes, glowing with that same cold, unnatural blue light, gleamed with an icy intensity that sent shivers down the spine of any who dared to watch them too closely.
For a breathless moment, the battlefield lay still. Your creations stood beside the monsters as they watched in tense silence their awe stricken eyes flicking between your summoned army and the enemy waiting beyond.
Across the snow-covered field, the Shadowbringer’s dark creatures stared back, their hollow, glowing eyes burning, and in the middle of it all was you and him.
Then, without warning, the stillness shattered. The Shadowbringer’s hand flicked through the air, and with that single motion, the battlefield erupted into chaos. His creatures shot forward like dogs let off a leash their twisted, unnatural forms racing across the snow with horrifying speed.
Their screams pierced the air, deep and guttural. It was a terrible, visceral noise reverberating through the battlefield as the shadows twisted and writhed, limbs stretching and distorting in grotesque ways as they rushed forward.
Your heart pounded, the pulse of magic in your veins thrumming, as the ice giants groaned to life beside you, the sound like glaciers grinding against each other. Their massive forms shifted, cracking and creaking as they prepared for the inevitable clash.
Then, with a low growl, the icy wolves leaped forward. Their paws scraped against the ground and the sound of cracking ice echoed around you as their armored bodies slammed into the advancing horde.
The clash was instant and fierce, an eruption of ice and shadow that filled the Snowdin. Your ice wolves leapt into action, their claws slicing through shadow creatures as if tearing through smoke. The creatures shrieked in response, reforming almost instantly, only to be torn apart once more.
The ice giants thundered forward, crushing shadows beneath their massive feet. A single swing from one of them sent a wave of shadow creatures scattering, their forms dissolving into mist before reforming in the distance.
However the shadows kept coming: relentless, ravenous. Tendrils of darkness lashed out, trying to ensnare your ice giants, wrapping around their legs like serpents. One giant groaned, momentarily faltering as the shadows threatened to pull it down, but with a defiant roar, it surged forward, smashing the tendrils beneath its foot.
"FOR THE UNDERGROUND!"
You turned, catching sight of Papyrus charging into the battle, his fellow monsters following his lead with a fierce battle cry that echoed across the battlefield. The monster's weapons and magic tore through the shadows. Ice wolves pounced on larger shadow creatures, their teeth ripping into them.
Overhead, Snowdrakes swooped low, their icy breath freezing enemies solid before the Doggo and Dogaressa shattered them completely.
But even as your allies pressed forward, your attention remained locked on the Shadowbringer. Across the battlefield, his dark eyes found yours. A faint, mocking smirk tugged at his lips, and lazily, as if bored by the fight, he flicked his wrist and summoned more shadow creatures. They rose from the ground like dark, twisted phantoms, writhing and swirling before launching themselves into the battle.
Anger crawled up your throat and with a growl you surged forward. Your sword appeared in your hand with a shimmer of blue light, the blade gleaming with the magic pulsing through you. You cut through shadow creatures as quickly as sucking in a breath, your magic answering every strike with ease.
With a flick of your wrist, a burst of water shot forward, slicing through another creature and sending dark mist swirling into the air.
The Shadowbringer watched your approach, mirth dancing in his cold eyes. He lifted his hand, and a wall of shadows exploded up between you. You didn’t hesitate. With a shout, you summoned a massive wave, water crashing into the shadow barrier like a tempest striking the shore. The collision was deafening, water and shadow colliding in a violent explosion of energy, swirling and crackling around you both.
But you wouldn’t let up. Slicing through the dissipating mist, your magic swelled as you carved your way through the dark tendrils, gusts of water crashing aside the shadowy creature trying to block you, and as you finally reached him, his smirk faded into something more vicious, his eyes narrowing as he called a jagged black blade into existence.
You struck first, your blade colliding with his in a blinding clash of sparks and magic. The impact jolted through your arms, magic pulsing from his blade making your grip falter.
The Shadowbringer sneered, his blade grinding against yours, trying to force you back. The clash rattled your bones, but you stood firm, your teeth clenched as you matched his mocking stare with your own.
With a grunt, you shoved him back, your swords separating with a screech of metal. You surged forward again, your sword flashing in an arc toward his side, but he was fast; too fast. His blade met yours with a resounding clang, parrying every strike you threw at him. Each of your attacks was easily deflected, as if he could predict your every move.
He swung downward suddenly, the speed of his attack catching you off-guard. You barely managed to raise your blade in time, blocking the strike. You hissed, twisting away just in time to avoid a follow-up slash. He was relentless, dark shadows swirling around him, his expression cold and detached as he moved with lethal grace forged from years of training.
His sword slashed low, aiming for your legs, but you dodged, rolling across the icy ground as shadows nibbed at your heels. Without thought, you launched a counterattack, your sword slashing through the air toward his chest. He dodged, but not fast enough, your blade nicked his arm,leaving a shallow cut. A growl escaped his lips, his eyes narrowing in fury.
Just as you take a step, pinpricks of pain erupt from your side, and you look down just in time to see a tendril coiling around you. Before you could react it wrapped around your torso, burning cold as it began to crush your ribs. A sickening crack filled your ears, and while you immediately cut it down, the damage was already done.
Your next breath was nothing but pain, and the Shadowbringer took full advantage of this weakness, slashing at you once more. Somehow you managed to block him, but the force knocked you off balance, his next strike grazing your shoulder. The sting of the cut brought a hiss from your lips, warmth spreading across your skin as liquid seeped from the wound.
“Is that all you’ve got?” he taunted, his voice low and venomous, though the sneer on his face was edged with a grimace of pain. He clutched his arm where you’d struck him, dark magic knitting the wound together, but it was slower than before. Ignoring the pain in your side and shoulder, you narrowed your eyes at him.
“You’re slowing down.” His smile faltered, a flash of irritation flickering across his face.
“I’m just getting started,” he snarled, summoning another wave of shadowy creatures to his side. But you weren’t backing down either. Drawing on your magic, water lifted from the snow, freezing into ice shards in less than a second. The shards hovered around you before shooting forward like arrows, aimed directly at him. He raised his sword, a barrier of shadows erupting around him to absorb the impact.
This time, you didn’t give him the chance to taunt you further and while he was distracted, you surged forward, ducking beneath his defenses and slashing toward his ribs.
His sword met yours just in time, but your momentum sent him staggering back. His eyes widened with surprise and frustration as he struggled to regain his footing. But even as you fought with renewed ferocity, the injuries were beginning to weigh on you. Every movement sent sharp pangs through your ribs, and your shoulder throbbed with every swing of your sword. Yet, you couldn’t afford to slow down.
The Shadowbringer, too, was beginning to show signs of wear. His movements, while still precise, were slower, less fluid. His smirk was gone, replaced by a grimace as he struggled to maintain control. Blood stained his sleeve, seeping through the dark fabric as he clutched his arm. His eyes, once gleaming with cold amusement, were now narrowed, filled with nothing but hatred.
With a cry, your chest twisted, and you summoned a torrent of water, crashing it down on him like a tidal wave. The force of it sent him skidding across the battlefield, with an exhale, you forced your feet to move rushing toward him once more. But you didn't even make it a couple steps before a massive tendril shot out from the ground, it slammed into you with bone-crushing force, sending you sprawling to the ground.
You gasped for breath, your vision swimming as you struggled to rise. The Shadowbringer loomed over you, his blade raised high, his expression cold and merciless. But just as he moved to strike, a flicker of hesitation crossed his face, his eyes briefly meeting yours.
And in that split second, you found your opening. With a burst of adrenaline, you rolled to the side, your sword slicing through the tendril that bound you. The Shadowbringer snarled in frustration as you lunged forward, your blade aimed at his chest.
Your blade connected, cutting through the dark fabric of his clothes and sinking deep into his side. There was a wet, sickening sound as the steel pierced through flesh and bone, the sensation reverberating up your arm. The Shadowbringer staggered back, his breath hitching in a sharp gasp that cut through the stillness around you.
For a moment, you just stood there, chest heaving as your hands still gripping the hilt of your sword buried in his side.
His eyes, once gleaming with cruel amusement, were now wide with fury and pain and for a fleeting second, you let yourself believe that it might be over.
But that hope was dashed when a low, menacing growl escaped his throat. His hand, slick with his own blood, shot out and grabbed the hilt of your sword, holding it in place.
You barely had time to react before his form began to shift, his body dissolving into a dark, swirling cloud of shadows. Your eyes widened in shock as his flesh seemed to unravel, black tendrils of smoke curling around your sword, devouring it like a hungry void.
Instinctively, you tried to yank your blade free, but it was too late, the shadows had consumed it, pulling it deeper into their blackened mass. The hilt slipped from your grasp, the cold metal disappearing into the swirling darkness, and before you could fully comprehend what was happening, the Shadowbringer completely vanished.
The shadows rippled and swirled around you, their presence suffocating and oppressive, blotting out the light. For a brief moment, there was nothing but the hollow echo of your own breathing, your heart thundering in your chest as you scanned the murky cloud for any sign of him. But the shadows did not remain still for long.
They shifted and coiled, and suddenly, with a sharp snap, they surged forward, lashing out toward you with the force of a whip. You barely had time to dodge, stumbling back as the tendrils of darkness swept past your face, the air hissing with their speed.
Then, without warning, the ground beneath you darkened, and shadows erupted from the earth. You barely had time to react before the Shadowbringer materialized to your side, his eyes blazing with fury, his arm outstretched as he summoned a massive ball of dark energy.
You gritted your teeth and summoned your magic, preparing to counter as you braced yourself, summoning a shield of water and ice in front of you. But the power of his magic was far greater than you anticipated. The moment he hurled the shadow orb toward you, it struck your shield with a deafening boom, shattering it instantly.
The force of the explosion sent you flying, pain shooting through your body as you were thrown across the battlefield. You barely had time to register the impact before you slammed into the ground, skidding across the snow and ice.
Pain exploded through your body, the air forced from your lungs as your back collided with something solid. You lay there for a moment, dazed, as the world spun around you.
Get up. Get up. You need to get up! The voice in your head screamed, repeating the mantra as you groaned, shifting to your side. Your vision blurred, your limbs heavy as you tried to push yourself up. Everything hurt: your bones ached, and the sharp sting of your injuries made it hard to breathe.
Blood dripped from your open wounds, staining the snow beneath you a deep crimson. The cold bit into your skin, but it wasn’t enough to numb the pain.
Through your hazy vision, you saw movement. The Shadowbringer was walking toward you, unhurried, like a predator toying with his prey. His eyes were cold, lighting up with the thrill of the hunt. The battle raged around him, monsters and shadow creatures clashed violently, but he paid them no mind.
You struggled to your feet, shaky as you wiped the blood from the corner of your mouth. Every step you took felt like a battle against your own body, but you forced yourself to stand, to face him. You couldn’t let him win.
Just as you were about to rush toward him again, something appeared in front of you, and for a moment, you thought you were hallucinating In front of you was what looked like a floating dragon skull. The thing hovered just inches away from your face, its maw opened wide, crackling with energy. You stared at it, confusion momentarily stopping you in your tracks.
What is this thing? Your eyes locked onto the skull, as the energy it emitted hummed against your skin, familiar in its strange way. Then recognition hit you like a wave crashing against rocks. This was Sans’ magic. Hope surged through your chest, tightening around your heart like a lifeline. The machine... Sans had done it. It's working.
Your pulse quickened as the Shadowbringer’s laughter snapped you back to reality. He was getting closer, his magic curling around him as his grin stretched wider, but you felt no fear. Not anymore.
You glanced at him, and his grin faltered ever so slightly, sensing the shift in you. Instead of rushing toward him, you stepped back, slowly at first. Another step, then another. The Shadowbringer's grin twisted into something else, his eyes narrowing. He was watching you now, not attacking. Not yet.
"Running away, are we?" His words dripping with disdain. Your heart pounded in your chest as you spun on your heel, sending a spiraling wave of water toward him. He dodged effortlessly, his form blurring for a moment before reappearing in the same spot, untouched. But you weren’t trying to hit him, just trying to buy yourself a few more precious seconds.
You turned and bolted into the forest, your breath coming in sharp gasps as you darted through the trees. The ground beneath your feet was slick with half-melted snow, yet you forced your legs to move faster, desperate to stay ahead of him.
His magic crackled and hissed behind you, bolts of shadowy energy slicing through the air, exploding the trees with enough force to send splinters flying in every direction.
You ducked as one of his attacks hit a tree just ahead, shattering it into pieces. Shards of wood rained down, and you could feel the sting of a few hitting your skin, leaving small, sharp cuts on your arms and face. But you didn’t stop.
The forest blurred around you, your vision narrowing to the path ahead as you weaved between the trees, desperately trying to stay out of his reach.
The strain of running was beginning to wear on you. Your lungs burned with each breath, pulling in the frigid air that stung against your throat. Your legs ached, muscles trembling with exhaustion as you pushed yourself harder.
The tendrils of water that curled around your body grew thinner, weaker, but you summoned more with every ounce of will you had left, sending them whipping back at him to meet his attacks.
But he wasn’t letting up. His attacks came faster, more vicious, each one more precise than the last. Dark energy crackled along the ground, splintering rocks and trees alike as he closed the distance between you.
You could feel the familiar icy cold of Snowdin slipping away as you led him deeper underground. The air was growing heavier now, clinging to your skin, weighing down each breath you took.
Snow gave way to dark rock beneath your boots and you could feel the moisture being sucked from the air as you drew closer to the Hotlands, and with it, your power seemed to grow weaker.
A sudden snarl echoed behind you, cutting through the thick air. You barely had time to react as a shadowy blade slashed toward your side.
You twisted your body just in time, feeling the heat of his magic skim past your skin as you dodged the strike. Your breath hitched as you gathered what little water remained in the air, forming it into a round ball of liquid and launching it straight at him.
It struck him square in the chest, the force of it enough to stagger him back for a brief moment. For a fleeting second, you thought you’d gained the upper hand.
But the heat of the Hotlands was unforgiving. The water evaporated almost immediately, sizzling into mist as soon as it hit the rocky ground. The once steady flow of water that had been your strength was now no more than a trickle, dissapearing before it could even reach him.
Your legs felt like lead, every step heavier than the last, your vision blurring at the edges as exhaustion set in. With a determined grunt, you forced yourself to keep moving, stumbling forward as you continued to lead him deeper into the Hotlands.
The rocky terrain grew hotter beneath your boots, each step sending sharp pangs of heat through the soles of your feet. The Lab was just up ahead, so close now that you could see its silhouette cutting through the waves of heat rising from the ground.
However, the Shadowbringer noticed your exhaustion. His grin widened, eyes gleaming with triumph as his attacks grew even more aggressive. Dark tendrils of magic lashed out, cutting through the heated air like whips. You twisted and turned, avoiding most, but one caught you off guard. It struck you hard across the side, sending you sprawling across the rocky ground.
Pain lanced through your ribs as you hit the heated surface, the impact knocking the breath from your lungs.
My ribs are definitely broken. You gasped for air, trying to push yourself back up, but your strength was slow to return.
The Shadowbringer loomed over you, his voice filled with cruel satisfaction. “You’re slowing down,” he sneered, watching as you struggled to your feet. “What’s wrong? Can’t handle a little heat?”
You didn’t answer. Couldn’t. Every breath felt like fire in your lungs, and your water magic responded sluggishly, trickling to your command rather than rushing as it had before. You managed to summon enough to form a weak barrier, just as his magic lashed out again, dark energy crackling through the air.
You blocked the first strike, but the second caught you across the arm, tearing through your sleeve and leaving a deep gash. The heat was unbearable now, the once sharp and fluid power of your water magic slipping further from your grasp. Your limbs trembled, your body protesting against the strain, but you couldn’t stop. Not when you were so close.
“Still standing?” His taunting voice filled your ears, and you felt the anger bubbling beneath your exhaustion. With a deep breath, you tried to resummon your sword, your palm flickering with light. You cursed under your breath, forcing more of your magic into your weapon but it didn't come. After a weapon is destroyed it took ten times more energy to replace it, something you were sure he knew.
Before you could move, his shadows surged forward again, faster and stronger. They wrapped around your arms and legs, yanking you down. You gasped as your body hit the ground, the heat searing against your skin as you struggled against the dark tendrils coiled around your body. They constricted tighter with every breath, pressing harder against your ribs.
You grit your teeth, trying to summon the last of your energy to break free, but your body was screaming with exhaustion. Each breath of air felt heavier, each movement more strained. Desperation clawed at your chest, but just when it felt like the shadows would consume you completely, a brilliant flash of light cut through the darkness.
A glowing spear hurtled through the air, striking the Shadowbringer in the shoulder with a sickening thud. His body jerked violently as the weapon embedded itself deep into his flesh. He let out a low, guttural groan of pain, his form flickering for a moment as the shadows wavered around you.
The dark tendrils loosened just enough for you to break free, your body stumbling forward as you scrambled to your feet. You were trembling, your breaths ragged, but you managed to look up, and what you saw filled you with a renewed surge of hope.
Undyne stood tall beside you, her one visible eye gleaming with the sharp focus of a predator on the hunt. A smug, confident grin tugged at her lips as she summoned another spear, the blue light of her magic shining brilliantly against the sweltering heat of the Hotlands.
"Looks like I arrived just in time to save your butt, huh?" she called, her voice full of the fierce, unwavering confidence that only Undyne could have. She smirked wider, her gaze locked on the Shadowbringer as she readied another attack. Her fingers tightened around her weapon, the muscles in her arms flexing as she angled her spear toward him.
You couldn’t help but let a small smile pull at your lips, despite the burning pain radiating through your body. “About time,” you managed, your voice hoarse.
The Shadowbringer staggered back, the spear still lodged in his shoulder making his movements sluggish. His magic flickered, weakened, but still dangerous and you couldn’t afford to waste the opportunity.
While he was distracted by Undyne’s attack, you gathered all the remaining moisture you could, pulling it into a concentrated sphere before launching it at his chest. The water struck him hard, sending him stumbling back several feet, his body nearly buckling from the force.
“Come on!” you shouted to Undyne as you turned on your heel and started sprinting toward the Lab. Your legs felt like lead, every step an effort as the sweltering heat only grew more intense the closer you got to the Lab's entrance. Undyne’s expression shifted from confident to frustrated as she narrowed her eyes, clearly confused by your retreat.
“Why are we running from the fight?!” she barked. You shook your head, barely managing to breathe through the burning in your lungs.
“He has to have some reason to follow me!” you called back, your voice strained. “If he thinks I’m scared, he’ll be more likely to take the bait.” Undyne let out a sharp huff, a small smirk curling her lips.
“Heh, your smarter than you look punk.” It wasn’t long before you reached the Lab, and the second you stepped inside, cool air blasted against for face, and you sighed.
Then, like a predator lying in wait, the shadows slithered along the ground, rising from the floor with terrifying speed. Their movements were swift, vicious, crackling with dark energy that burned your nose. You barely dodged the first strike, throwing yourself to the side as a tendril slammed into the spot where you’d just been standing, leaving a jagged gouge in the floor.
Undyne was beside you in an instant, her spear cutting through the air in a wide arc, intercepting another attack. The shadows hissed angrily as they recoiled from the contact with her magic, but they didn’t retreat for long. They lashed out again, even more ferocious than before.
Undyne’s muscles tensed beneath her armor as she swung her spear, eye blazing. The tendrils faltered under her relentless assault, but they kept coming, their speed almost unnatural, darting in and out the shadows from which they came from.
You summoned what water you could from the air, launching it in sharp bursts. You gritted your teeth as exhaustion began to creep into your limbs.
"You holding up?" Undyne shouted over her shoulder, her voice strained.
“Barely,” you managed through clenched teeth, dodging another tendril as it slashed toward your legs.
"Good!" she barked with a sharp laugh, spinning her spear to cut through yet another strike. "BECAUSE THIS FIGHT IS FAR FROM OVER!"
Just as the words left her mouth, the air thickened, a sharp chill spreading through the room. The shadows coiled tighter, and the temperature seemed to drop as the Shadowbringer emerged from the darkness.
Undyne’s grin stretched wider, her grip tightening around the shaft of her spear until her knuckles turned white. Without even hesitating, she threw herself toward him, her body a blur of motion as she charged. The roar that erupted from her throat was a guttural sound filled with fury and raw, burning hatred. Her spears flew from her hands, whistling through the air in brilliant arcs of blue.
But he moved like smoke. His body twisted and slid between her attacks, shadows coiling and curling as he dodged, his feet barely touching the ground. Tendrils shot out in retaliation, snapping toward Undyne in less than a second. Her feet shuffled back instinctively, planting themselves as her spear swung in a wide arc, blocking the strike just in time.
“THIS IS FOR ASGORE, CREEP!” She roared, voice trembling with emotion, her arms shaking as she drove her weapon forward. Then, with a sharp, vicious slice, her spear slashed across his cheek. The blade tore through the shadowy mist of his form, leaving a jagged, deep mark that made his entire body shudder.
The flicker of pain in his eyes was fleeting, but it was there. Visible, for just a moment. The shadows that enveloped him recoiled, wavering as if disturbed by the damage. His expression twisted, lips curling into something dark and dangerous, his eyes narrowing into cold slits.
In a blink, his wrist flicked and the shadows responded instantly, surging toward her in a wave of dark energy. Undyne barely had time to react. The force slammed into her chest with a deafening crash, the impact so powerful it lifted her off her feet.
The sound of her body hitting the wall echoed through the room was an awful, sickening thud of armor and bone meeting unforgiving metal. Her spear slipped from her grasp, clattering to the floor as her body crumpled in a heap, unmoving.
“UNDYNE!” Your scream tore from your throat, but the sound felt distant, drowned beneath the roar in your ears. Fury ignited inside you, searing and white-hot. Your vision blurred at the edges, every thought clouded with rage, until the only thing you could focus on was him. The Shadowbringer. The creature that had hurt your friend.
Without thinking, your legs propelled you forward, your body moving faster than your mind could catch up. The air around you thickened with magic, water gathering from every available source, swirling around your arms in sharp, jagged currents.
You could feel the heat of it, the magic crackling in your veins, but all you knew was the blinding need to hurt him. To make him pay.
You lunged, sending the gathered water crashing into him with every ounce of strength you had. The impact was satisfying. His magic disintegrated on contact, shattering into nothing as the water surged forward, pushing him back. His shadows flickered, and for a split second, you felt the surge of hope.
But his snarl cut through the air, low and furious. His eyes locked on you filled with seething malice, and before you could react, his tendrils whipped out in a blur of motion. One struck you hard across your side, the force of it sending you flying. Your body skidded across the floor, the cold metal scraping against your skin.
Your feet scrambled as you tried to stay upright and you barely managed to land on them, legs trembling from the shock of the blow. Breathless and exhausted, you slid to a stop beside Undyne, your chest heaving as you fought to remain standing. As you brace yourself for another attack, your muscles tight, a voice cut through the battle, one you faintly recognize.
“Fear not, darlings! Mettaton is here to save the day!” You blinked, momentarily caught off guard. A robot stepped from the shadows, tall and sleek. His body was impossibly polished, reflecting the glow of the flickering lights above.
The screen that made up his face shifted into a beaming grin, as he struck a heroic pose. One arm stretched out in front of him, fingers splayed toward the Shadowbringer as though he were commanding the very air itself, while his other hand rested confidently on his hip.
Did I hit my head too hard? Mettaton’s voice was thick with exaggerated confidence, the kind that instantly demanded attention. Even the Shadowbringer stopped, seeming baffled as he stared at the new face.
“Now, be good little heroes and run along,” he purred, casting a flamboyant wink in your direction. “I’ll handle this dastardly villain!” You blinked again, still reeling from the unexpected entrance of this... whoever he was. Still, his arrival bought you time, time you desperately needed.
“Uh... right,” you muttered, quickly turning your focus back to Undyne. She groaned as she attempted to push herself off the ground, her hands shaking against the metal floor, muscles twitching from the strain. Her face twisted in a grimace, pain flickering across her face. “Let’s go!”
You bent down beside her, reaching out to grab her arm and hoist her to her feet. Undyne’s breath came out in harsh gasps as she struggled to stand, her body trembling with effort. She gritted her teeth, one hand gripping your arm tightly for support while her legs wobbled beneath her. Her eye flicked toward the fight behind you, anger burning through the pain.
“Come on, Undyne,” you urged, relief filling you as she finally stood upright.
“I got it…” she rasped, though the way she trembled betrayed the exhaustion she tried to hide. Her feet shuffled awkwardly beneath her, but she kept her balance, straightening with a stubbornness that was pure Undyne.
Together, you stumbled forward, moving as quickly as her weakened body would allow. Your heart pounded as you navigated the twisting halls of the Lab, the sounds of battle echoing behind you as the robot voice bounced off the walls.
You couldn’t help but glance back, half expecting the Shadowbringer to be hot on your heels. Instead, his snarls of frustration filled the air, accompanied by the crackling clash of magic as Mettaton, somehow, held him at bay. You had no idea who this robot was or why he was so confident in taking on such a powerful enemy, but it seemed thr distraction was working.
As you you ran, you cast a glance at Undyne. Her face was stoic, but beneath that, you could see the strain. Every step seemed like an effort, her body barely holding together, but she pushed on not allowing you to slow down for a moment.
“Who the hell is that guy?” you asked, breathless from both exhaustion and confusion. Undyne let out a sharp breath, half a scoff, half a chuckle.
“Just some… annoying show-off robot.” She grunted as she stumbled over a crack in the floor, and you quickly steadied her. “But damn, I’ll take the help.” You snorted, nodding in agreement.
Undyne's arm was draped heavily over your shoulders, each of her steps laborious and shaky. The metal underfoot echoed with every shuffle of your boots, the faint hum of the CORE in the background growing louder with each step, and when you finally stumbled into the main chamber you were tempted to collapse to the floor in relief.
Sans and Alphys were already there as Alphys was frantically typing commands into the nearby console, her eyes wide and jittery behind her glasses. Sans stood a few feet away, looking more alert then you had ever seen him.
The moment Sans saw you, his expression shifted, eye sockets widening slightly as he took in the bruises on your face, the shallow cuts that lined your arms, and the way your body trembled from the effort of keeping Undyne upright. He rushed toward you, his eyes briefly darting over your injuries before settling on your face.
"hey, you okay?” His bony hand rested lightly on your shoulder, and you could feel him scanning you, looking for anything you were hiding.
“I’m fine. For now,” you replied, though your voice wavered. The pain was impossible to hide as you shifted your weight, barely able to keep your knees from buckling. You gestured to the CORE with your chin. “Anything I need to know?”
Sans’s eye flashed to the machine, then back to you, as he stepped closer,his voice lowering, “yeah. If you get caught in the pull you'll go in the machine right along with him, so when it’s time, i’m gonna flip the switch and teleport us outta here. No way I’m lettin’ you get caught in this mess. I’ll make sure it’s just the Shadowbringer who gets sucked in.”
Before you could respond, a quiet groan escaped Undyne as she shifted her weight. Her legs wobbled, and you tightened your grip on her arm, trying to keep her steady. The movement caught Alphys’s attention, and she instantly rushed forward, abandoning her place at the console.
“U-Undyne!” Alphys gasped, her eyes wide with concern. She knelt beside you both, her hands hovering awkwardly over Undyne’s arm as though afraid to touch her for fear of making it worse.
“Are you… are you okay? I-I didn’t think you’d-" Undyne grunted, trying to straighten up, but her knees buckled beneath her and you followed her to the ground. She gave a weak chuckle, her lips pulling into a pained grin as she looked at Alphys.
“Heh… didn’t think you cared that much,” she rasped, voice strained but teasing. Alphys’s face flushed with a mixture of panic and something softer. Her hand found its way to Undyne’s cheek, hesitant but full of worry.
“Of course, I care! You idiot… I-I’ve always cared. I just-” Her voice cracked, and she quickly swiped a hand over her eyes, shaking her head. “You’re so reckless…” Undyne’s smirk softened, the fire in her single eye dimming just enough to reveal the emotion underneath. Her hand moved, slow and shaky, but it found Alphys’s, and she squeezed it lightly.
“Alphys… I’ve loved you from the beginning, y’know?” she muttered, her voice softer than you've ever heard it, “You’re the smartest… dorkiest scientist I know.” For a moment, the chaos seemed to blur, fading into the background as the two locked eyes.
Undyne’s pain was there, but so was a fierce affection that lit up her face in a way that no injury could dim. Alphys blinked rapidly, her face reddening as she stammered something incoherent, but her hand didn’t leave Undyne’s.
But the moment didn't last long. A low, cold laugh echoed through the chamber, freezing the blood in your veins. You stiffened, instinctively stepping between the sound and the others as the Shadowbringer materialized from the darkness. The sound of metal scraping against metal cut through the air like nails on a chalkboard, and your stomach twisted in horror.
Dragging behind him was Mettaton. More accurately, Mettaton’s head. The sleek, polished surface was now marred with deep gouges, wires sparking and dangling from the neck. His once gleaming screen flickered erratically, a lifeless, cracked eye barely clinging to its former brightness.
The Shadowbringer held the robot by the mangled remains of his neck, metal screeching as he dragged him across the floor, each step punctuated by that terrible, visceral sound. A trail of oil, like blood, marked the path behind him, dark and sickeningly thick.
“Pathetic attempt to slow me down,” the Shadowbringer sneered, tossing Mettaton’s head to the side with a casual flick. It clattered to the floor, rolling once before coming to a halt, the dim light from the screen fading into nothing.
“Breaking the robot wasn’t even worth the effort.” Undyne, despite her weakened state, staggered in front of Alphys, her spear materializing in her trembling hand.
“Stay behind me,” she hissed, not taking her eye off the Shadowbringer. The Shadowbringer’s gaze shifted toward you, and for a moment, a flicker of something crossed his face, and his grin widened, his hands falling behind his back.
“Quite fascinating, really,” he drawled, taking a step closer. “If I didn’t know better, I’d say you’ve been trying to lure me here.” Your heart skipped a beat, but your face remained stoic.
Though, he could see it in your eyes and his attention flicked to the CORE, then back to you, and his grin twisted into something darker, more sinister.
"Ah," he mused. "You know, I can feel the power radiating from this machine... What exactly is it you thought this would accomplish?" He took a step closer to the CORE, his form towering over the humming machinery as he tilted his head. "Were you hoping to destroy me with it? No…" He let out a chuckle, the sound echoing off the cold, metal walls.
"You're too weak to kill me. Too afraid."
The weight of his words pressed down on you like a crushing force. Your heart hammered in your chest, the air suddenly feeling too thick, too heavy. A sickening dread settled in your stomach, twisting and tightening with every step he took closer to the machine.
He knows Your body tensed, muscles coiling with the urge to act, but your feet felt rooted to the floor. He let out another low, dark laugh.
"Whatever your plan was, it ends here." Before you could scream a warning, his hand shot out, black tendrils of shadow exploding from his fingertips, twisting and writhing toward the CORE.
"Stop him!" The words tore from your throat. "Don’t let him—"
But it was too late.
It slammed into the CORE with a violent force, and the room erupted in chaos. The hum of the machine turned into a screech of grinding metal, the whirring energy that once pulsed steadily now flickering in wild, unpredictable bursts.
Sparks flew in every direction, the blinding light flashing through the chamber. The sharp crackle of electricity buzzed through the air, and the acrid stench of burning wires stung your nose.
The ground beneath you trembled violently, a low, rumbling quake shaking the lab as if it, too, were recoiling from the Shadowbringer’s assault.
You stumbled, your legs barely holding you up as the floor buckled beneath your feet. The machine groaned under the strain, its intricate mechanisms failing, sputtering, and sparking as the dark magic tore through its core.
Undyne, let out a furious battle cry. Her eye burning, despite the blood trickling from the corner of her mouth. With a forceful push, she surged forward, summoning a barrage of spears from thin air.
"DIE YOU BASTARD!" she roared. The spears shot toward him, but he was ready. With a flick of his wrist, the shadows lashed out again, grabbing the spears mid-flight and effortlessly snapping them in half.
"Pitiful," he sneered. Your stomach lurched as the Shadowbringer advanced on the CORE, his shadows spreading like ink, consuming everything they touched. You clenched your fists, your heart pounding in your ears as you felt the sting of helplessness settle in.
“Undyne!” you shouted, trying to steady your voice despite the overwhelming dread tightening in your chest. "You need to grab Alphys abs get out of here, now!"
Undyne's jaw clenched, her muscles taut as she struggled to rise again, ready to charge. But the strain of the fight was wearing on her, every movement slower, more labored. So instead of fighting, she stood, staggering in front of Alphys and placing herself between her and the machine.
"Come on!" she growled under her breath.
Alphys looked conflicted as she clung to Undyne's arm. "B-but the CORE! It’s-it’s gonna-" Before she could finish, the CORE emitted another screech of tearing metal, a huge arc of electricity exploding from its side. The entire lab shook, and the lights overhead flickered, threatening to go out entirely.
The Shadowbringer, undeterred, raised his hand once more but suddenly stopped. Sans’s eye socket flared with a brilliant blue light.
The air crackled with power as he raised a hand toward the Shadowbringer, his left socket blazing with that same unnatural hue. The Shadowbringer's chest glowed and he barely had time to move before he was launched backward into the wall.
The Shadowbringer staggered to his feet, brushing off the debris with a look of grudging respect. His lips curled into a slow, dark grin as he narrowed his eyes at Sans.
“I’m surprised,” he admitted. “You’re more powerful than I thought.”
“don't go gettin' too attached," Sans interrupted, voice as casual as ever. He popped his knuckles lazily, unfazed as he shoots him a grin. "You might say I’ve got a bone to pick with you.” The Shadowbringer’s grin faltered, his eyes narrowing further.
“You think this is a game?”
“nah, but I am pretty good at dodging,” Sans replied with a wink before vanishing in a flash of blue light. The Shadowbringer’s shadows lashed out, tendrils snapping toward where Sans had stood just a moment before. But Sans reappeared behind him, launching a volley of sharp, glowing bones that shot through the air like a bullet.
The Shadowbringer growled in frustration, his tendrils flailing wildly as he tried to strike Sans from every angle. Sans, teleported effortlessly out of the way each time and with every flicker of blue light, he was gone, reappearing behind the Shadowbringer or at his side, launching more bone attacks, that even the Shadowbringer couldn't dodge.
Their fight became a blur of movement and every time the Shadowbringer thought he had Sans cornered, the skeleton would slip out of his grasp, his grin only widening with every dodge.
“you really oughta chill out,” Sans quipped, narrowly avoiding a particularly vicious swipe. "you're startin' to lose your cool." The Shadowbringer’s snarl deepened, his tendrils whipping faster, more erratic, feeding off his growing irritation.
“You are testing my patience skeleton!” Sans teleported again, reappearing behind him with a chuckle.
"good thing patience is a virtue, huh?" But the Shadowbringer was done playing. With a snarl, he unleashed a powerful strike, a tendril coiling like a serpent before lashing out with terrifying speed. This time, Sans was a fraction too slow.
The magic slammed into his side, the force of the impact sending him flying across the room. He crashed into Alphys and Undyne, the three of them tumbling into a tangled heap on the ground.
"Sans!" you shouted. Alphys scrambled to her feet, crawling out from underneath the pile as she pushed her glasses up her nose, her face pale.
"Th-the CORE!" she gasped, her voice trembling with panic. "It’s destabilizing! If he keeps this up-" A deafening crack echoed through the room as the Shadowbringer’s dark energy struck the CORE with a violent blast. The machine groaned under the strain, sparks flying from its damaged surface.
The steady hum of the machine faltered, sputtering and coughing, as though it were on the verge of tearing itself apart. Alphys’s hands flew to the console, much to Undyne's protests, her fingers moving frantically across the buttons.
"I-I’m trying to stabilize it, but the magic’s too unstable! If we can’t stop it, it’s going to create a wormhole, a massive one! It could take out the entire Underground!" You paled as ground beneath you trembled, the walls vibrating from the energy building in the room.
Your eyes shot to the Shadowbringer, who stood at the center of the chaos, his lips curling into a cruel grin as the CORE continued to shudder and spark. His tendrils wrapped tighter around the machine, feeding more and more dark energy into it.
Without a second thought, you charged at him, your body moving on pure instinct. You slammed into him with all your strength, tackling him to the ground. The impact knocked him off balance, but even as you struggled to pin him down, his shadows coiled and writhed beneath you, fighting back,.
“You think you can stop me?” he hissed, his voice cold and venomous as he tried to shove you off. His shadows lashed at you, grazing your skin. But you held on, your muscles screaming with the effort.
From behind you, you could hear Alphys shouting. “I-I can’t stop it! The machine’s going to- ” The ground beneath your feet trembled, as though the very foundation of the lab was being torn apart.
Every nerve in your body screamed to move, but you pushed it down, your jaw ticking as the Shadowbringer tried to escape. Each strike sent waves of pain coursing through your body, but you gritted your teeth, your grip on the Shadowbringer tightening. You couldn’t let him reach the machine.
The whine of the failing circuits grew louder, and you could feel the air thickening with the unstable energy of the forming wormhole. It pulsed like a living thing, an expanding mass of white light threatening to devour everything. Your eyes widened, your chest twisting. This wasn't how it was supposed to go. Now. Because of you, everyone was going to die.
As time seemed to slow your mind drifted back to Frisk and Papyrus. They had believed in you, given you their faith and hope. The realization hit you like a wave, crashing over you. You had promised to protect them, and you had failed.
The air around you felt thick, as your eyes found Sans, and when your eyes met his, it was as though the entire world fell away, leaving just the two of you suspended in time. It was then you knew, with an undeniable certainty, what you had to do. San's eyelights widened, as your eyes glowed a deep blue, and his permanent smile fell.
"don’t you even think about it!" he shouted, raw fear creeping into his voice in a way you hadn't heard before. Your chest tightened, heart hammering against your ribs as you pulled in a shuddering breath. Your magic flared, your breath coming out in a white cloud, your veins burned, your magic pulling on the last of your reserves.
"I'm sorry," you whispered; His sockets widened, the blue flame in his socket flaring. With trembling hands, you pressed your palms against the cold, trembling ground. Summoning your magic from deep within, you felt the water in the air shift, the moisture gathering and swirling in response to your call. It built, gaining momentum, a vortex of shimmering blue that pulsed around you like a heartbeat.
The Shadowbringer snarled beneath you, shadows writhing with renewed fury as he realized what you were doing. His tendrils lashed out harder, desperate to break free, but you pushed down with all your might, ignoring the sharp pain that erupted through your body with each hit. Y
"no!" Sans’s voice broke through again, piercing and frantic, but you couldn’t stop. Not now, and with a final, guttural cry, you released the magic.
The ground beneath you shook as a wall of ice surged upward. The ice grew taller, thicker, stretching between you and your friends. The ice surged and twisted around you and the machine, forming a gleaming sphere that began to solidify into back ice. The ice continued to build, closing in on all sides, sealing you the machine, and the Shadowbringer himself, into a shimmering, impenetrable prison
The cold bit at your skin, but it was nothing compared to the ache in your chest. On the other side of the wall, you could hear your friends' muffled shouts, confusion, fear, and desperation. Sans's voice rose above them, frantic and pained as he shouted your name.
The Shadowbringer bucked beneath you, shadows writhing like snakes, but you held firm. Ice spread from your hands, crawling over his body, freezing him in place. His movements slowed, the dark magic he wielded flickering as the cold wrapped tighter around him, layer after layer of ice encasing his form.
"Fool," he hissed, his voice strained and choked as the ice closed around him. "You'll be taken too." Tears pricked the corners of your eyes, but you blinked them away.
"So be it." you murmured, your voice barely audible over the roar of the building wormhole. Behind you, the machine let out a deafening crack, the light from the wormhole now blinding as it expanded. The world around you was a blur, but your focus locked onto one thing. Sans.
His voice, raw and broken, pierced through the noise, the desperate edge to it cutting deep into your soul “NO! you can’t do this!” His voice, usually so steady, so detached, was unrecognizable in its panic.
His fists pounded against the ice wall, the solid surface keeping him from reaching you. His form glitched, magic flickering around him as he tried in vain to teleport to you, but the energy from the machine was so unstable that even his power was failing.
“please,” his voice cracked. “i need you." You squeezed your eyes shut, the heat behind them painful. Your body was numb now. Even as the Shadowbringer’s relentless shadows struck you, the pain barely registered anymore. You were beyond feeling, every nerve in your body dulled.
Frisk... Papyrus... Their faces flickered briefly in your mind, Frisk’s soft smile, Papyrus’s laugh, and for a moment, your heart ached. You wished you could see them again, hear their voices, share one more second together. The machine sputtered violently, the light growing more intense, and you knew you didn’t have much time.
Taking a shuddering breath, you turned back toward Sans. Through the thickening ice, his silhouette was faint, distorted by the light and magic swirling around you. But his eyelights, were still so clear, filled with a grief that mirrored her own.
“Sans,” you whispered, voice barely audible over the roar of the vortex and you weren't sure if he could hear you. The tears you had fought so hard to suppress welled up, spilling over as you pressed your hand against the ice. “You gave me a home… you gave me a family.”
He was pounding against the wall with everything he had, but his strikes slowed, his hand shadowing yours. His mouth moved, forming words you couldn’t hear, but you knew. Knew he was begging you to stop, to not leave him, to find another way.
“So let me protect it,” you continued, voice trembling as your throat tightened. “Even if it means… I have to say goodbye.” A weak, broken smile tugged at your lips, though it hurt more than anything to do it. You could barely see through your tears now, but it didn’t matter. You had made your choice.
The light behind you grew blinding, and as the warmth of it surged over you, you felt an odd sense of peace. It was ironic, really, that it would end like this, so much like how it had all begun.
The world trembled as the vortex howled louder, pulling at you, and tugging you closer to the machine’s core. Your fingers went slack, releasing their hold on the frozen Shadowbringer, and your eyes fluttered shut. The cold was gone now, replaced by a warmth that seeped into your bones.
As the light engulfed you, you thought of Sans, of Frisk, of Papyrus. Of the friends you had made, the bonds you had forged. And even though your heart ached, there was peace too.
“Thank you,” you whispered.
And then, everything went dark.