Archive of Our Own ^beta

Chapter Text

Yukio sat in his small cubicle in the Exorcist True Cross Order Japan Branch Office,  fingers drumming lightly against his desk. The room was dimly lit, the only illumination coming from his laptop screen and the soft glow of the city outside. 2:22 AM.

He sighed. Another sleepless night.

This wasn’t new. It had been this way for years. Even as a child, he never truly felt tired at night. At first, he thought it was the stress, the training, the missions, the pressure to stay ahead. But it wasn’t just that. Even when he had the chance to rest, his body never seemed to demand it the way it should.

Instead, the night felt... natural. The darkness didn’t weigh on him. It sharpened him. His thoughts were clearer, his reflexes faster, his body too steady.

He leaned back in his chair, rubbing his temples.

It wasn’t human.

The thought crept in before he could push it away. No. He was human. He didn’t have flames, a tail, or fangs. He wasn’t like Rin. He wasn’t like them.

Then why did his body work the same way?

His phone buzzed. He already knew who it was before he checked.

"U up?"

Yukio exhaled sharply. Of course Rin was awake.

—

Rin

Rin had been tossing and turning for hours, but sleep refused to come. His body felt charged, awake, restless. It wasn’t just a little insomnia, he wasn’t tired at all. His senses were sharper, his energy buzzing under his skin like he’d just downed five energy drinks.

The dorm was silent. Kuro was sleeping beside him.

With a groan, Rin sat up, raking his fingers through his hair. Kuro stirred. Rin petted the black cat and looking to the night sky, His window was open, letting in the cool night air. He hadn’t noticed before, but now it felt strangely comforting, almost inviting. He grabbed his phone. 2:22 AM huh. Naice time. 

Without thinking, he moved.. graceful, smooth, too quiet. He landed on the floor with a softness that felt unnatural.

Outside, the world was alive.

Rin leaned on the windowsill, looking out over the True Cross Academy rooftops. The wind carried distant sounds an owl’s cry, the faint rustling of leaves, the softest footsteps of something moving far below. He shouldn't be able to hear those things.

And yet, he did.

The darkness wasn’t just comforting… it was clear. His eyes adjusted immediately, as if there was no difference between day and night. He could see everything, down to the smallest details. The moonlight wasn’t blinding, the shadows weren’t obscuring.

His heartbeat picked up.

"This wasn’t normal.” But his life had never been normal, had it? So… 

“ ah, whatever!"

He grabbed his jacket and put it on then swung his legs over the windowsill and dropped onto the grass below, landing soundlessly. That, too, was wrong. He should’ve made some noise. He should’ve felt the impact more.

Kuro meowing from the windowsill “Rin You can't sleep with me….again?”

Rin snorted. “Aren’t you supposed to be nocturnal?”

Kuro flicked his tail. “Yeah, but I can sleep whenever I want. You, on the other hand…”

Rin groaned, grabbing his phone. 2:23 AM.

Bet Yukio was awake too.

"U up?"

A few seconds later, his phone vibrated.

"Yeah. Can't sleep. You?"

Rin smirked. Knew it.

Without hesitation, he typed: "Same. Wanna get ramen?"

A pause. Then: "Fine. Meet me at Ramen Takuka-ya."

Rin looked up,”kuro do you wanna go with me.” 

Kuro meowing and stretching, “no Rin, my dream was great i want to continue it!”

Meanwhile, across campus, Yukio closed his laptop, rubbing his eyes before reaching for his coat.

—

The night air was crisp as Yukio walked through the academy grounds, his coat pulled loosely around him. The world felt different at this hour…. quieter, softer. The usual rush of students, the hum of lectures, the constant noise of life… it was all gone.

It was peaceful.

His boots barely made a sound against the pavement. He had always been light on his feet, too light. It wasn’t something he had trained for, not consciously. He just… moved that way.

Too quiet. Too natural.

He sighed, shoving his hands into his pockets. He wasn’t tired. He should be, after a long day of training exwires, reviewing mission reports, handling his classes. A normal person would be exhausted. A normal person would be asleep.

But Yukio had never been normal, had he?

As a child, he convinced himself it was discipline. He worked harder, pushed himself beyond his limits. If his body didn’t break, if his mind didn’t shut down, it was because he was strong.

But now, after years of sleepless nights, after too many moments of still being awake when the rest of the world had shut down, he wasn’t so sure.

Rin struggled with sleep too.

That thought settled in his mind, cold and unshakable.

At first, he assumed it was because of Rin’s flames… and his body wasn’t human anymore. Of course he had trouble adjusting. But Yukio? He had no reason to be this way. No tail, no fangs, no fire licking at his skin. Just a normal human body.

But was it?

His footsteps slowed. He frowned.

He had spent his whole life telling himself he wasn’t like Rin. He wasn’t a demon. He wasn’t like the- that demon abomination. But there were things… small things.. that he never spoke about.

How he never truly felt tired at night.

How he could function on very little sleep, even as a kid.

How the dark never unsettled him, how he moved too quietly, too smoothly when walking at night.

How his hands never shook during late-night missions, but they did when forced to be awake early in the morning.

He always assumed it was just training, discipline. But now, a chilling thought

Maybe it wasn’t just stress. Maybe it wasn’t just years of conditioning. Maybe…

Maybe it was something in his blood .

The idea made something twist in his chest. He had spent his whole life trying to be human, proving he was human. But what if his body had never been, even before the flames failed to take him?

The thought lingered as he reached the small ramen shop Rin always dragged him to. The neon glow of the sign flickered, casting a dim blue light over the empty street.

Rin was already there, leaning against the wall outside, hands stuffed in his hoodie pocket. He looked up, grinning.

“You took your time.”

Yukio rolled his eyes. “It’s called walking like a normal person.”

Rin snorted but didn’t argue. He pushed open the door, and the warm scent of broth and noodles greeted them.

Yukio stepped inside, shaking off the night’s thoughts.

—--

The small ramen shop was nearly empty, save for an older man in the corner sipping his broth. The warm scent of simmering pork and miso filled the air, the soft clatter of chopsticks and the low hum of a radio making the place feel almost unreal… like a quiet pocket of existence separate from the rest of the world.

Rin and Yukio sat at the counter as the owner, Takuka-san, worked behind the stove.

Takuka was an old man with a permanent scowl, his wrinkled face half-hidden under the shadow of his tied-back gray hair. He was the kind of guy who never had anything nice to say but still made sure your ramen was always hot and fresh when you showed up.

As he stirred the pot, he glanced at Rin with his usual gruff tone. “Tch. Surprised you’re even eating here. Thought you were too good for other people’s cooking.”

Rin smirked, leaning his elbow on the counter. “Oi, I don’t turn down good food. It’s just that most ramen places suck.”

Takuka clicked his tongue. “Brat.” But he still ladled the broth with care, setting down two bowls in front of them.

Yukio adjusted his glasses. “It’s true, though. He used to refuse to eat out at night.”

Rin shrugged, grabbing his chopsticks. “Yeah, well, I was busy cooking my own.”

That part was true. Back at the dorms, while the rest of the world slept, Rin was in the kitchen.

It wasn’t just a habit.. it was a need. His body wouldn’t let him rest, so he spent his nights simmering broths, testing flavors, perfecting every detail. His hands had to be busy. His mind had to focus on something. Cooking gave him that.

And because of that, he had become picky as hell. Most ramen shops didn’t get it right. Either the broth was too salty, the pork wasn’t tender enough, or they skimped on the right seasonings. It always felt lacking.

But this place?

He took a slow slurp of the broth. This was good. Because it wasn’t just Takuka’s ramen anymore.

It was his. 

Yukio raised an eyebrow. “You still haven’t told me how you ended up eating here so much.”

Rin grinned, setting down his chopsticks. “Simple. I fixed it.”

Takuka scoffed. “You say that like my ramen was garbage before.”

Rin ignored him. “First time I came here, the broth was too salty. I could tell he was covering up weak flavors with extra seasoning. So I gave him a tip… use more kombu and let it soak longer. Next time, it was better. So I gave him another tip. Then another. Now…” Rin gestured at his bowl, grinning. “It actually tastes right.”

Takuka wiped his hands on a rag, rolling his eyes. “Damn brat thinks he’s some ramen god.”

“Oi, I never said that,” Rin shot back. “But I do know what I’m talking about.”

Takuka grumbled something under his breath but didn’t argue. Because he had listened.

Yukio shook his head, taking a slow bite of his own ramen. “…You’re unbelievable.”

Rin just smirked. “What? You like it, don’t you?”

Yukio sighed but didn’t deny it.

They ate in quiet understanding, the warm broth settling in their stomachs. Midnight ramen wasn’t about conversation. It was about existing in the same space, in the quiet of the night, where words weren’t needed.

Neither of them belonged in the day.

But here, under the night sky and the dim ramen shop’s lights, they didn’t have to.

Chapter Text

They were Satan’s sons. born of a god of destruction and a human woman who had once believed she could bridge Heaven and Hell with love. Both had inherited power. Both had inherited the potential to call things that should never be called.

For Rin, that power manifested as blue fire, the cosmos burning in his veins. For Yukio, it was subtler, colder. His eyes could see the structures of contracts, the invisible chains that bound demon to summoner. He could feel the resonance of names not meant to be spoken.

And sometimes, when he slept, he heard them.

We could serve you, whispered the shadows behind his eyelids.
We could make you powerful.

He always woke before he answered.

—--

It began with the dream.

A sea of ash stretched into eternity, each grain glimmering faintly as if it remembered fire.
The sky was colorless, neither day nor night, only the soft hum of something breathing beneath the surface.
In the distance stood a tower  immense, black, and ancient. At its peak rested a single book, open and waiting.

When Yukio drew closer, he could see words written across the pages, names in a language that should not exist, yet he understood them perfectly. Each name pulsed faintly, as though alive.

And when he looked long enough, one name would shift, flicker, rearrange itself into his own.

That was when he woke.

Every night, he would sit upright, heart hammering, cold sweat tracing his spine.
And every night, Rin would wake moments later, gasping.

They never spoke of it.

—

Life went on, or at least, pretended to. Rin overslept, burned his breakfast, argued with his classmates, laughed too loudly. Yukio attended his lectures, trained new recruits, answered bureaucratic nonsense with military precision.

They walked the same paths, spoke of trivial things, meals, patrols, the weather.
And beneath it all, the dream simmered like an ember neither could smother. 

It happened again on a quiet afternoon.

The sky hung heavy with rain. Rin sat on the dormitory roof, tuna mayo onigiri on his fingers, watching the clouds turn silver. He tried to stop this but.. sometimes- many times the night calling him, because of the silence it gave him.

He didn’t notice Yukio until his brother’s shadow crossed the tiles.

“You’re up here again,” Yukio said softly, stepping closer.

Rin shrugged. “Couldn’t sleep.”

Yukio didn’t respond immediately. He just stood there, looking out at the sky, his reflection faintly visible in the sheen of rainwater pooling between tiles.

Then, almost casually: “You saw it again, didn’t you?”

Rin froze. The wind shifted.

He didn’t ask what. He didn’t need to.

“…Yeah,” he said after a long pause. “You too, huh?”

Yukio nodded once. “It’s getting clearer.”

Rin exhaled. Spurting warm tiny blue fire from his lips. The smoke drifted up, blue-tinted, curling like script across the air.

“I keep hearing something,” Rin murmured. “When I wake up. Just before I do. Like someone’s calling my name.”

“I hear it too,” Yukio said. His eyes flickered, almost glowing in the dim light. “But it’s not calling. It’s offering.”

“Offering what?”

Yukio looked at him, and for a moment Rin saw a glint, fear, maybe, or recognition.

“Names,” Yukio said. “Power. Servants. The right to command.”

Rin snorted softly. “Like we need more of that.”

But the humor didn’t stick. The silence after it was heavy, uneasy.
Rain began to fall, pattering softly against the roof tiles.

—

That night, the dream changed.

They stood together this time, side by side on the sea of ash.
The tower rose before them, impossibly tall, its shadow falling over the horizon.

The book at its peak was open again, but this time, the pages turned themselves.
Each name it revealed burned faintly blue or white or black. Some of them hissed. Some of them wept.

Rin felt his skin crawl.
Yukio stepped forward, his gaze fixed.

The wind whispered around them, carrying a single voice — low, ancient, and endless.

Just call, it said. And we will come.

Rin turned sharply to Yukio. “Don’t.”

“I’m not,” Yukio said. But his voice trembled.

“You’re hearing it.”

“I always hear it.”

The ash swirled around their feet like mist. Somewhere in the distance, something vast and winged moved- a shadow in the sky, patient, waiting.

Rin reached out, grabbing Yukio’s wrist. The touch was grounding, human.

“Wake up,” Rin hissed. “Now.”

The tower began to glow. The book turned another page.

Just one name, the voice whispered. The first will obey.

Rin shouted- and the dream shattered like glass.

—-

When Yukio opened his eyes, dawn light was spilling into the room. His brother sat on the floor nearby, trembling, the faintest flicker of blue beneath his skin.

Between them, the shadows seemed thicker, darker, and for a heartbeat, Yukio could see the threads again: faint chains winding through the air, linking the two of them to something unseen, something waiting just beyond the reach of waking.

He closed his eyes. The air felt too still.

Rin spoke first, voice barely above a whisper.
“Do you think it’s gonna stop?”

Yukio didn’t answer.

Outside, the church bells began to ring, faint, distorted, out of rhythm.
Neither of them moved.

Because they both knew the sound wasn’t coming from the chapel.
It was coming from within.

Chapter Text

The shooting range at True Cross Academy was unusually quiet that morning- save for the sharp crack! of Yukio’s gunfire slicing through the air. The smell of gunpowder hung heavy, mixed with the faint bite of coffee so dark it could probably ward off low-level demons.

Each shot hit dead center. Not a millimeter off.
The younger students watched in reverent silence.

“Wow, Okumura-sensei’s a machine,” one whispered.
Another added, “Does he even blink?”

He didn’t.

Yukio adjusted the slide of his pistol with surgical precision, jaw tight, expression unreadable. His movements were too smooth, too measured, less like a 15 year old boy shooting targets and more like something ancient remembering how to move in human skin.

Professor Neuhaus stood behind him, arms crossed, a cigarette dangling from his lips. His mouth twitched, though it wasn’t clear if it was irritation or… something darker. “You make it look easy, Okumura-sensei,” he said finally.

“It’s just pattern recognition,” Yukio replied calmly, reloading.
“Pattern recognition,” Neuhaus echoed dryly, exhaling smoke. “Most people call it instinct. Or luck. Or demonic affinity.”

Yukio didn’t look up. “I prefer math.”

“Of course you do.” The older man’s tone was bitterly amused. “A little human word to make it all sound less... infernal.”

A door slammed open.

“YUKIOOOO!”

Every head turned. Rin burst into the range, hair sticking up in all directions, eyes bright with the kind of energy that made normal people nervous.

Yukio’s sigh was almost theatrical. “Nii-san, what did you do this time?”

“Nothing!” Rin protested, which immediately confirmed he had done something. “Okay… maybe something. I tried to help with kitchen duty and accidentally melted half the counter.”

Neuhaus pinched the bridge of his nose. “How does one accidentally melt a counter?”

Rin shrugged helplessly. “The soup was too spicy? I mean.. i used 999 carollina reapers”

Yukio muttered, “the- but.... how?” Yukio sighed and shook his head “whatever… You’re a walking fire hazard.”

Rin grinned. “Yeah, but I’m your favorite walking fire hazard.”

—-

When the students left, only the three of them remained. Neuhaus stubbed his cigarette out against the wall and said, almost too casually, “You know, Okumura-sensei, I’ve seen exorcists train twenty years and never reach that level of precision.”

Yukio holstered his guns. “I had a good teacher.”

“Fujimoto was a good man,” Neuhaus said slowly, “but not that good.”

The air shifted, just enough to make the shadows stir. Rin looked up from where he was fiddling with a bullet casing, suddenly serious.

Neuhaus met Yukio’s eyes, his voice quiet but sharp. “You know what I think? I think you inherited more than anyone wants to admit.”

“Careful,” Yukio said softly. “That sounds like blasphemy.”

“Or truth.”

A sharp, distinct clap! clap! echoed in the room.

Rin’s grip tightened on Yukio’s arm. “Uhh… I think we should go. We need to tell Mephisto about the… counter…”

For a few tense seconds, Yukio only stared into Neuhaus's eyes, the reflection distorted by his glasses. Rin worried that Yukio might start a fight, but when Yukio finally gave a curt nod and walked out of the classroom, Rin exhaled in relief. He sent one last glare at Neuhaus before quickly following his brother.

Neuhaus watched them quietly, two brothers, one burning, one calculating, both pretending to be normal.

He turned away with a scoff. flicking his cigarette butt into the spent shells littering the floor. The ember hissed out, but the thought didn’t.

“Pretending,” he muttered under his breath. “That’s what they do best.”

Outside, Rin’s laughter echoed down the corridor, loud and alive, chasing after Yukio’s clipped footsteps. The sound was almost enough to convince anyone they were just two rowdy brothers, one too serious for his own good, the other too chaotic to sit still. Almost.

Neuhaus knew better.

He’d seen demons masquerading as saints. He’d seen exorcists lose their souls in the name of order. But those two? They were a paradox wrapped in human skin, one boy carrying light that burned, the other shadow that reasoned. He couldn’t decide which was more dangerous.

He smirked to himself, adjusting his exorcist coat. “A priest’s sons,” he murmured, “and neither one blessed.”

—-

Down the hall, Rin caught up to Yukio, nearly tripping over his own tail. “Hey, wait up! You didn’t have to stare him down like that. He was just-”

“-testing me,” Yukio cut in, tone flat. “That’s what he does.”

“Still! You could’ve at least thrown something back.” Rin tried for a grin. “You know.. like, ‘sorry, I left my demonic charm at home today!’”

The attempt fell flat.

Yukio’s silence stretched, his boots echoing on the polished floor. “I don’t like being compared to him,” he said finally, voice so low it barely carried.

Rin blinked at the sudden shift in tone. The humor drained from his face as quickly as his tail stilled. “...To who?” he asked, already knowing the answer.

Yukio’s hands were in his pockets, but the tension in his shoulders was sharp enough to cut glass. “To Satan.”

The word hung in the air like smoke from a gunshot, invisible but choking.

Rin rubbed the back of his neck, searching for something to say, something that didn’t sound like fear. “You’re not him, you know,” he muttered. “Neither of us are.”

Yukio stopped walking. “Aren’t we?” His voice wasn’t angry, it was quiet, clinical, like he was stating a diagnosis he didn’t want to believe. “We don’t burn like humans do. We don’t tire like they do. We don’t even dream like they do, Nii-san.”

Rin looked down. His tail curled nervously around his ankle. “Yeah, well, we don’t destroy worlds either.”

For a moment, Yukio didn’t respond. His reflection in the window beside them looked too calm, too composed, like it didn’t belong to the same person whose eyes sometimes glowed faintly blue under the right light.

"hey let's just forget that.. What do you want for today's dinner?"

Yukio sighed, adjusting his collar. “Dinner, huh?”

Rin perked up slightly, grateful for the change. “Yeah. I was thinking something normal. Like curry. With actual vegetables this time, not whatever Mephisto calls ‘nutrient sailormoon cubes.’”

“I’ll pass,” Yukio said, already turning toward the dorm exit. “I told you, mission in Chiba. 23:34.”

Rin groaned. “You even time your missions by the minute? Yukio, that’s not dedication, that’s-”

“-efficiency.”

“No! That’s creepy!” Rin threw up his hands. “You need sleep, man! A nap! Maybe two! You’re running on caffeine and spite.”

Yukio didn’t slow down. “Then make the bento extra strong.”

“Don’t ‘make it strong’ me! I’m serious!” Rin jogged to catch up again, nearly tripping on his tail for the second time. “When was the last time you slept more than three hours?”

“I knew this was coming,” Yukio muttered under his breath, dry as ever.

“Yukio!” Rin frowned, stepping in front of him this time, blocking the door. “You can’t keep doing this to yourself! You think I don’t notice, but you’ve got that look again, like you’re seeing ghosts or something.”

Yukio’s eyes flicked up. For a heartbeat, they glowed faintly, a pale, unnatural light that had nothing to do with the sun streaming through the window. “Maybe I am.”

Rin’s stomach dropped. “...What?”

Yukio brushed past him, voice low. “Forget it. You’ll be late for dinner.”

“Yuki-”

“Rin.” He turned just enough to meet his brother’s eyes. “Don’t worry about me.”

That was Yukio’s way of saying you should.

Rin watched him go, his tail flickering uncertainly. “Dinner’s still waiting, you know!” he shouted after him. “Even demons need carbs!”

Yukio raised a hand in half-hearted acknowledgement before disappearing down the hall.

For a long while, Rin stood alone in the empty corridor, listening to the fading sound of Yukio’s boots against the floor. Then, faintly, just faintly.. he heard it again.

We could serve you.

Rin’s tail froze mid-sway.

He looked around the empty hall, heart thudding. “...Yukio?”

But the voice didn’t come from him. It came from the shadows.

And when Rin turned, he could’ve sworn he saw faint blue symbols pulsing under the glass of the classroom door, Circles that looked too much like summoning seals.