Chapter Text
Kaeya knew he was a selfish person. How else could someone keep so many secrets from those that trusted him, sneak around their backs, deceive those around him? As a traitor to this nation, his love for it could be nothing but a lie.
And he knew right now, the most optimal choice would be to step back and let the Knight of Favonius do their duty. A monster would be vanquished. The one person who knew Kaeya’s secret would disappear.
So he could call it nothing but a selfish desire that he refused to let that happen.
A red glow brightened under Diluc's shirt, before flames burst free. Lava seemed to burn away his skin from the inside, crawling up his neck and arms, spreading from the burning core in his chest. He choked and coughed, his entire body spasming in pain.
Kaeya reached out, cryo forming at his finger tip. Maybe if he used his element to keep the fire at bay, it would slow his transformation. But Diluc’s hand slammed against him, shoving him back as flames flickered in the air.
“Get away from me!” Diluc snarled, staring at him with terror and anguish in his eyes. It was the same wild look he had given Kaeya right before he had disappeared last time. “Not again... I don’t want to see it again,” he seemed desperate, pleading toward Kaeya.
The Knights of Favonius watched in horror and confusion, trying to understand what they were seeing. Jean looked to Kaeya, “What is going on, Sir Kaeya? I can try to help Diluc but is the Scourge Knight coming here?”
Kaeya bit his lip for a moment, cursing himself. It was now or never. “It’s him.”
Jean's eyes widened snapping back to Diluc, watching as the flames engulfed Diluc’s form. “No, he can’t be...”
“He’s the Scourge Knight,” Kaeya confirmed. “He didn’t want anyone to find out. That was why he was trying to avoid us. I told you... the last thing he would try to do was ask for help.”
Diluc let out a scream as his knees buckled, burning hands clawing at the dirt. His skin had turned to molten fire and his eyes glowed. “What can I do? I know I didn’t do the right thing, but I can’t change it!” he yelled at the earth before his voice turned to a sob, “Is there no way I can change?”
Watching him bargain with the coming dawn, Kaeya realized that it was more than the pain of the transformation causing him to writhe, but he was seeing something within his mind. Could it be-Kaeya swallowed as understood Diluc's reaction, that look in his eyes. His mother had placed a curse on Diluc, that should he ever hurt Kaeya, he would bear the Khaenri’ahn curse. Not only was this transformation literal physical torture but it was also was forcing him to relive those moments they had crossed blades.
No wonder Diluc had avoided him. He had been conditioned to expect pain at the sight of him. What twisted magic. Kaeya wished he could break the spell but he had been too young when he left to remember little more than the basics of Khaenri’ahn magic.
He... barely even remembered what his mother had looked like.
“There has to be something we can do for him!” Jean cried, stepping forward. A wave of heat buffeted them back, threatening to more than sear a few hairs.
Albedo intervened, gesturing for her to stay back, “Master Jean, he has been affected by the Scarlet Quartz. We believe he may become aggressive and volatile under its influence.”
Her brows knit together with concern, “Is it reversible?”
“I don’t know.”
Diluc had gone limp, his body slumping over. For a moment Kaeya worried the transformation had actually killed him before tendrils of dark energy snaked around his limbs. It formed into plates of black black armor, covering the molten form of his body like a second skin. As the abyssal knight finally took form, he did not move.
Kaeya swallowed, hesitantly reaching a hand out, “Diluc?”
Glowing ember eyes flashed from within the knight’s dark helm. A shiver ran down Kaeya's spine as he stared into the creature’s gaze, some uncanny certainty telling him that the thing looking at him was not Diluc.
He leapt back as flames arched through the air in front his face, the heat baking his skin. That broken blade had formed in the creature’s hands, flames licking across the metal as he dragged it forward. The burning glow from within grew brighter, fire bursting free from the gaps in the black armor, burning wings taking form as the Scourge Knight stepped closer, hand tight against the hilt of his weapon.
As Kaeya stumbled back, he felt a moment of deja vu. His hand hesitated as he reached for his rapier, just as he had all those years ago, “Diluc, please don't do this. I don’t want to fight you.”
The Scourge Knight lifted the blazing sword. Once again, his words seemed unable to reach Diluc.
But this time as the blade came down and Kaeya unsheathed his sword, cryo energy raced across the length of rapier. Dancing out of the way of the attack, frost raced across the ground and froze the knight where he stood. This time he did not have to rely on the miracle of the gods to save him.
“We need to restrain him!” Kaeya yelled to Jean. “He might calm down after burning off all this energy.”
She nodded, seeming to understand, but her brows were furrowed, “We’ll do what we can.”
Kaeya almost jumped as Albedo stepped next to him, “If you can keep him occupied for a minute, I may be able to create a construct to hold him.”
Looked to Jean, Kaeya tilting his head with a grin, “Hear that? All we need to do is buy some time.”
Before she could respond the Scourge Knight gave a monstrous roar, shattering the shackles of ice. His burning gaze turned to Kaeya, charging toward him.
“Knight of Favonius!” Jean yelled to the other knights, “From rank and protect Chief Albedo and Sir Kaeya!”
The ranks of knights intervened trying to stop the Scourge Knight from reaching Kaeya but with a sweep of his massive sword, the abyssal knight knocked them aside. Several tried to attack from behind, but the fiery wings flared, blasting them back with a wave of heat.
Kaeya gripped his rapier, looking for an opening to slip past. Elements wise, he was at a disadvantage. And there was little he could do against that burning greatsword.
As the Scourge Knight broke through the knight’s ranks, a bolt of lightning struck the abyssal creature, stunning him in his steps for a moment. Lisa walked past Kaeya, giving him a wink, “Don’t fret yourself. Leave this one to us,” she said as she lifted her glowing lantern into the air and more lightning rained down.
A gust of wind picked up, sweeping away the dust and smoke, the air turning fresh and light. Jean lifted her sword, calling out to the knight around them, “Don’t give in! We must keep fighting to protect Mondstadt.”
The knight rallied, charging once again at the Scourge Knight. Even with Jean’s power bolstering them and Lisa’s lightning, the abyssal knight did not falter, fire and ash burning the air around him as he kept attacking. Whenever Kaeya saw a chance he jumped in, cryo energy temporarily restraining him. But the ice never lasted long. If anything... the temperature of the Scourge Knight’s flames seemed to only be increasing.
Golden runes and circles formed under their feet, forming a massive array around the Scourge Knight. As it completed, Albedo called out, “I’m ready!”
“All units, retreat!” Jean ordered, falling back.
Pillars of earth burst out from the ground, wrapping around the Scourge Knight in a twisting cage. The abyssal knight was encased by stone, unable to move. He let out a roar of fury, fighting against the bonds.
For a moment Kaeya wondered if they had succeeded. Thoughts of how long they could keep him here crossed his mind, running through possibilities. Could they move him? Was there somewhere safe they could keep him? What if... he never turned back?
But the Scourge Knight had a different method of escape. With a flash of abyssal energy, he vanished, leaving the stone cage completely empty.
Flames burst over the sky above them, mixing with the glare of the rising sun. The Scourge Knight reappeared, blazing wings out stretched in the air. Lifting his broken blade, he lifted it up and like a burning comet, plunged back into the earth
The ground cracked, heat and flames erupting up under their feet. Kaeya was knocked from his feet, thrown into the air. He tumbled across the ground, his chest spasming and as he tried to inhale, the air burning in his lungs.
All around him, fire roared. Most of the knights around him were on the ground, struggling to move. Kaeya could see the fear in their eyes. In front of them the Scourge Knight continued to burn, the air rippling from the heat.
Albedo took a step forward, planting his hand against the ground as he tried to summon another geo construct, the abyssal knight grabbed him, hoisting him into the air and throwing him aside like a doll. Kaeya felt his heart hiccup with fear as he watched the alchemist go flying.
“I can’t let you continue to do this,” Jean still stood, raising her sword to face the Scourge Knight. “I don’t want to hurt you, Diluc, but you leave me no choice.”
She was right, Kaeya realized. They had to stop the Scourge Knight here. In this state of rampage, he would burn down the Dawn Winery. There would be nothing stopping him from attacking Springvale or the city of Mondstadt next. And if Diluc really was bearing the curse of the Khaenri’ahns then there was little that could harm him. They would have to attack with everything they had.
As the abyssal knight lunged forward, Jean side stepped the attack, winds cutting along her blade as she pierced the joints of his armor. One of the wings swept toward her and Kaeya forced himself to move but he knew wouldn’t be able to reach her before the flames did.
There was one way he could get there in time... his eye flickered around, feeling all the other eyes watching him. So many people would see- they would know.
The flaming wing slammed into Jean. She managed to buffet its force with a gust of anemo but Kaeya could see the flare of heat from the air that burned her. She was beginning to flag. Turning, the Scourge Knight lifted the massive sword above her. There would be no way to dodge this attack.
Kaeya pulled his sword back to strike and stepped through the abyss. He felt the space squeeze around him before he popped out right behind the abyssal knight. There was a break in the black armor, where the crimson blade had pierced him before. He could easily running his sword into the monster, piercing straight into its core from here-
But he hesitated.
What would happen to Diluc?
His hand shook and in a moment of selfish impulse, his rapier sliced into the back of the creature’s knee, a blast of ice tearing at the joint. The Scourge Knight snarled, a clawed hand swinging around and grabbing Kaeya.
It slammed him to the ground, but Kaeya couldn’t help but smile a little. At least he managed to distract the abyssal knight. Maybe Jean would have the willpower to make the strike he couldn’t.
Feeling the heat against his skin as he lay at the mercy of the raging creature, Kaeya wondered if the outcome of this fight had been predestined from the start. It always seemed to go this way.
“If you ever wake, don’t blame yourself. This isn’t you,” he said weakly, looking up into the glowing eyes above him. “Did you know, I never stopped looking for you? You could have come back. I wouldn’t have cared what you were.”
The creature’s claws tightened around his throat and he choked, struggling to breath, but still he tried to get the words out.
“I just want my brother back.”
His hand slipped down the black armor as his strength failed. He waited for his vision to fade and his mind drift into that eternal darkness, but instead air rushed into his lungs. The heat started to fade. Abyssal magic tingled across Kaeya’s skin. This was... his doing.
Where Kaeya’s hand touched the Scourge’s knight’s claws, the black armor peeled away, revealing a human hand underneath. The core in the Scourge Knight’s chest flicked and the rest of the armor began to crumble away, the flames smoldering into smoke.
As the last of the embers turned to ash, the smoke brushed against Kaeya’s cheek. A woman’s voice whispered softly into his mind, “You’ve grown so much, my little star. I’m sorry I had to leave you, but remember, I’ll always love you, no matter the distance between us.”
Tears ran down Kaeya's face as Diluc slumped against him. As the ash in the air slowly settled, he didn’t move, holding the man in his arms. Diluc groaned, slowly shifting. There was a pause as he seemed to realise where he was.
“Kaeya?” he mumbled. He seemed confused. “Am I... alive?”
A shuddering breath exhaled from Kaeya’s throat and he nodded. “The curse is broken.”
Diluc stared at him, giving him a blank look of disbelief before his eyes widened. Relief seeped into this expression, his eyes watering as he collapsed into Kaeya arms, sobbing gasps of breath shaking his chest. Kaeya let him.
For a moment it felt like they were brothers again.
Footsteps crunched toward them, Jean hurrying over. Her vision was aglow, healing wind at her fingertips. “Are you two alright? ”
At the sound of her voice, Diluc stiffened as if only now remembering that Kaeya was not the only one here. He straightened up, wiping his face as he looked toward her, “I’m fine-”
“He’s been stabbed,” Kaeya countered.
Jean stepped close as Diluc begrudgingly showed her the wound. To Kaeya’s relief the corruption of Scarlet Quartz seemed to have completely disappeared. One unintended benefit of the abyssal transformation he supposed.
As she began to heal the wound, Diluc took in the destruction around them. “I’m sorry...” he said quietly.
She looked at him, quiet for a moment, “You are the Scourge Knight?”
He gave a small nod, unable to keep eye contact.
“He was cursed,” Kaeya cut in. “But,” he paused as tried to think of some way to explain without implicating himself, “getting stabbed by Scarlet Quartz broke the spell... after causing one last rampage.”
Jean’s brow furrowed together. Under her elemental power, Diluc’s wound closed, not completely healed but no longer life threatening. She looked up at him as she finished, “Why didn’t you say anything? We could have helped you.”
Diluc’s gaze fell, avoiding her. “It wasn’t your concern.”
“Not our concern?” Jean stared at him. “Just because you are not a knight anymore does not mean that you are not still my friend. I care about your wellbeing.”
Kaeya shot Diluc a look, muttering under his breath, “I told you so.”
Diluc rolled his eyes in irritation at the jab, but his comment made Jean turn to Kaeya. He quailed as her gaze hardened.
“You’ve been working with him since he came to Mondstadt, haven’t you?” she asked.
“I didn’t know everything,” Kaeya tried to explain. “I only found out the Scourge Knight was Diluc when he saved me...”
“I still have some questions I’ll need answered later.” Kaeya swallowed, remembering that he had used abyssal powers in front of her. She had seen him teleport. But in an unchartistic display of affection, she grabbed them both, hugging them close. “I’m glad you two are safe. Please don’t do anything like that again.”
Diluc gave a nod and Kaeya chuckled, telling her, “I try not to make a habit of risking my life recklessly.”
“Yet that never stops you from doing dangerous stuff,” she muttered as she pulled back. “Please don’t forget we want to help.”
Kaeya was quiet, ruminating on her reaction. It seemed that he hadn’t raised her suspicions of his heritage or at least it wasn’t a present concern... for now.
“Where’s Albedo?” he asked, looking up.
Around them the Knights were regathering, tending to injuries and assessing the situation. Kaeya could see that many of them had burns of varying severity. They had embarked from Mondstadt ready to fight a monster, but not one made of fire.
Jean’s mouth pursed, as she looked around at the state of their company, “Could you look for him? I’ll begin healing the worst of the injured.”
Standing, Kaeya began to look around for the blond hair of the alchemist when Diluc nudged him, nodding to the woods. “Over there.”
Kaeya spotted Albedo’s white coat leaning next to a tree and hurried over. The alchemist lifted his head as they approached. He nodded before wincing. One of his legs was splayed out, a makeshift brace formed out of geo energy. “Mind helping me up?” he asked.
“Did you break your leg?” Kaeya exclaimed.
“It’s not as bad as it looks. Once I get back to my lab, I’ll be able to heal it myself,” Albedo said as Kaeya pulled him up, seeming wholly unbothered by his predicament. Looking toward Diluc, he said, “I see you must have figured out the condition for the curse.”
Kaeya gave a subtle nod, glancing around. It wasn’t really something he wanted to talk about with so many knights around.
Albedo seemed to understand, “I’m sure you’ll explain it all later. For now, I’m glad to see the issue seems to have resolved itself.”
Kaeya helped him hobble back over to the rest of the knights. With most of the major injuries patched up, they were beginning to prepare to head back to the city. Jean paused, looking back at Diluc who was keeping distance from the rest of them.
“Would you like to come back with us?” she asked.
Diluc hesitated for a moment and then glanced back at the winery behind them. “I think I would like to stay here for a little longer if that is alright.”
She nodded, but held back, “Sir Kaeya, could you...”
“I’ll stay and keep an eye on him,” he promised. A part of him was relieved to have an excuse. He wasn’t sure if he was ready to leave Diluc alone after every time the man had disappeared on him.
“Thank you. We’ll talk when you get back.” she said.
Kaeya nodded, keeping his gaze on the ground. He knew he could only avoid suspicion for so long. Try as he might, he had always been an outsider.
“Master Jean,” Diluc spoke up, “don’t blame him for what happened. I was the one who lied to him. If anyone should receive punishment, it should be me.”
Jean tilted her head, “Don’t worry. Those who deserved punishment for today’s events have already received it. Your involvement was an unfortunate accident. One that was resolved quickly thanks to Kaeya’s help. I will not let any harm befall him.”
He gave a bow of gratitude, “Thank you.”
As the knights made their way out of the valley, Kaeya found himself staring at Diluc. The man huffed as he noticed him staring.
“What are you looking at?” he grumbled.
“You didn’t have to say that,” Kaeya said, fiddling with a buckle on his coat. “Aren't you worried you'll take the blame as the Scourge Knight?”
“Would you rather her interrogate you about why you came to Mondstandt?”
Kaeya didn’t respond. As they walked toward the Dawn Winery, Adelinde was waiting for them, fretting over their scrapes and bruises. She and the other staff hurried to prepare some food and tea to help.
“I thought you wouldn’t care,” Kaeya finally said.
Diluc’s head swung toward him, those red eyes staring through him for a moment. In retrospect he wondered how he hadn’t recognized the burning gaze of the Scourge Knight. “You didn’t ask for any of this.”
Kaeya blinked in surprise.
Giving a sharp breath, Diluc broke eye contact. “After I was cursed, I found myself trapped between worlds. I could no longer be human but I could not begin to grasp the world beyond that. It felt so isolating. I was all alone.” He looked back at Kaeya, “I imagine you must have been like that when you first stepped foot into Mondstadt.”
Swallowing, Kaeya could not answer. He had not expected the one person who had once shattered his hope on finding belonging here to be the one to understand him. It seemed his transformation had changed him, not just physically.
“Diluc,” Kaeya said slowly, “Before you transformed, you said some things... Did you mean that? Or was it just an impulse of the moment as you thought you were dying?”
Diluc’s eyes flickered away again. “I meant every word. I’m sorry.”
For some reason, he’d prepared himself for the worst. He wouldn’t have blamed Diluc for spouting nonsense as what would have been his consciousness came to an end. It somehow seemed almost more difficult to believe that Diluc really had meant to apologize. “I see... that must have been the condition.”
There was a pause before Diluc asked in return, “Kaeya, how did you break the curse?”
“I... forgave you.”
For a moment Diluc didn’t say anything. Fidgeting, Kaeya leaned forward to see his expression. The man’s brows were pinched with confusion. “Why would you do that?” he asked.
Kaeya gave a long sigh. “Maybe because I didn’t want to see you turned into a mindless abyssal monster. Maybe I still had questions I wanted to ask you...” he fiddled with Vision for a moment and then added, “Maybe during those days when I was with Scourge Knight, it made me realize I missed you. Little did I know you were by my side.”
“You don’t have to forgive me.”
“I know,” Kaeya hummed to himself, “But maybe I saw there was still hope.”
“You think so?” Diluc asked quietly.
Kaeya tilted his head, giving him a mischievous smirk, “I guess we’ll see.”
The door to the Dawn Winery opened, Adelinde stepping out. “You’re still out here?” she called out. “I've got a fresh pair of clothes for the both of so you can change out of those ashes covered things. And there's food, hot and ready. We’re all waiting for you two.”
Glancing toward Diluc, Kaeya watched him with cautious hesitation. “Are you going to stay this time?”
There was a pause as Diluc looked up at the horizon, tears brimming in his eyes as he watched the sun rise in the brightening sky. “I think I will.” His gaze turned toward the Dawn Winery, a wistful smile spreading across his face. “It’s been a long time since I’ve been able to enjoy a simple meal.”
In the warm light of the morning dawn, they walked back to the winery together. Kaeya felt there was a strange comfort with the footsteps next to him, reminding him of the brother he had once walked alongside, or the abyssal knight he had fought beside. Once Kaeya had trusted him with a secret he had told no one else, believing that his brother would understand.
And four years later, Diluc finally did. Maybe the curse had never meant to torture him. Perhaps Kaeya’s mother had placed that curse predicting Diluc would one day turn against the brother he claimed he would never betray, or maybe she had hoped that her spell would make him realize that Kaeya was still the brother he had loved. Perhaps in a world, Diluc would have come back for help and they could have broken the curse in days. But days had turned to weeks and months, yet it had only been on the verge of the curse consuming him completely that Diluc had finally returned to Mondstadt.
“Welcome back home,” Kaeya told Diluc as they stepped back into the winery.
Diluc tilted his head, “It’s your home too.”
And as Kaeya stood beside him, he realized that maybe he wasn’t as alone as he thought.