No specific pronouns mentioned
Warnings: Spoilers for Kaeya’s backstory and friendship level cheracter story, Character death, A lot of mentions of blood, Angst with an ending that I guess could be counted as comfort but also could not I dunno??, I give my OPINION on what I think could go down with Khaenri'ah but it’s also just me bullshitting to set the scene for the pain so don’t come after me about it being inacurate, I also know this isn’t really how Celestia works but shhhh yes it is.
Written mostly for @ashelexa who wanted me to write them angst. Enjoy the pain, bestie. This made me cry and I don’t even simp for him.
I also wrote it at 3 am in a splurge of creative energy so there may be some grammar mistakes and whatnot.
Kaeya had always known this would be his fate. Since the very moment he set foot in the Knights of Favonius as a member of their ranks, the question had echoed endlessly through the broken abyss that was his mind. If war should ever break out as his people had always intended, what side would he take? On one hand, there was his blood family. The father who he had been born to, but who had abandoned him at the first opportunity. On the other, there were the people of Mondstadt. People who, despite knowing nothing about him, had welcomed him with open arms. The people who had given him a family held together not by the bonds of blood, but by trust, loyalty, and undying devotion to one another.
Now, in the face of the war that for so long he had been expecting yet dreading, his question had been answered. He belonged to neither side, his divided loyalties tearing him apart from the inside out. His own people, the ones who had sent him there in the first place, had turned him away. After all, what good was a soldier who was unable to truly dedicate themselves to their cause. What good was a soldier who could turn on them at any moment under the disgusting influence of love and friendship from the very people they called their enemies?
The people of Mondstadt, on the other hand, had been blinded completely by the searing pain of betrayal. They didn’t want to believe it, none of them did. Their Captain. Their hero. Someone they had placed their lives in the hands of willingly for years, had been there only as a spy. As someone present solely for the purpose of bringing them down when they were at their weakest. He had pleaded for their forgiveness, begged with everything he had. After all they had been through together, he could never hurt them. But after the years of lying, there was no way they could be sure that these were not simply more heartless lies. They, too, had turned him away, telling him that if he truly wanted to prove himself, he would have to do so in battle.
Now, stuck in the middle of an endless war with his own mind, he turned to the one person he had left. The one person who he had hurt the worst by far, yet who stuck by his side nonetheless. You.
“Why didn’t you tell me?” you begged, voice broken and raw from the sobs that ripped through your throat. “We could have worked something out. You should have told me. I could have protected you. I-”
Your words were cut short as he reached up to cup your cheek gently in his hand. His strength was leaving him, you could feel it. Even with the horrific battle raging in a seemingly endless tide around you, the only thing you could focus on was him. The love of your life, who now lay bleeding out in your arms. Win back their trust in battle, he had been told. And that was exactly what he had done. Fight for them. Win for them. Die for them.
“You can’t blame yourself,” he pleaded, looking up at you through pain clouded eyes. Even through the pained look, you could still see the love and adoration in his gaze. “There was nothing you could have done,” he assured you. “I would rather die a million deaths here than have put you in harm’s way with the weight of such a heavy secret.”
“No, no.” You shushed him quickly, gently rubbing a thumb over his scarred eye and down his cheek, wiping away the tears that he had tried and failed to hold back for your own sake. “You won’t die here. I won’t let you. You’ll make it through this, and everyone will welcome you back, I’ll make sure of it,” you promised him. He could feel his heart ache at the blatant pain in your voice. He could see in your eyes that you knew as well as he did that your words held no truth. Even so, you refused to give in to the harsh reality.
“You have to let me go,” he whispered, reaching his other arm up weakly to hold your face in his shaking hands, his thumbs swiping away the heavy tears that rolled freely down your cheeks. “You have to promise me that you’ll live for me. If you were to die here too, my sacrifice would be in vain.” Another sob tore through your throat at his words and you clutched him closer to your chest, burying your face in his matted hair as the truth of his situation finally settled upon you. He had lost too much blood now. Even if you could reach Barbara and the rest of Mondstadt’s medical team on time, there was no guarantee they would take him in.
“I’ll remember you,” you swore to him, pressing your lips against the top of his head. The strong metallic scent of blood overwhelmed your senses, but you could care less. All that mattered to you now was these last moments you had with your lover. “And someday, when my time reaches me, we will meet again in Celestia.”
“Celestia,” he snorted at your words, the sudden intake of air sending him into a fit of coughs that ripped violently through his body. When the coughing had ceased, blood dribbled from the corners of his mouth. He smiled weakly, forcing a sarcastic laugh as he wiped it away. “Celestia would never have me. I’m a lying traitor. You truly think the god’s would want someone like that amongst their numbers?” he chuckled dryly. You pulled away from him so that you could look him in the eyes, your gaze filled with stubborn determination.
“No,” you objected quickly. “You’re so much more than you think. Kaeya, you’re a hero. You’re my hero.” Your voice cracked at those words and you took a moment to gather yourself before continuing. “No traitor could ever have done what you did here today. While your mind may have been conflicted, your heart was with the people of Mondstadt. It always has been. You put your life on the line to protect those people, and they’ll remember you as a hero throughout all of time. I promise you that.” Tears filled the corners of Kaeya’s eyes once again as he stared up at you, vision growing increasingly blurred.
“Archons, what did I ever do to deserve you?” he laughed weakly, tangling his hands into your hair to pull you against his chest with whatever strength he had left. You laughed at his words, shaking your head against him.
“You didn’t have to do anything. You already deserve the world,” you responded, pulling away only to lean in again and press your forehead to his. His gaze softened, his signature smirk crossing his face even through the ever growing pain he was experiencing.
“Funny,” he hummed lightly. “Because you are my world.” You laughed weakly again between the sobs that once again bubbled in your throat at the slowly dying light in his eyes.
“I love you,” you sobbed as he once again reached to cradle your face. “So, so much.” You closed your eyes, tears dropping from them and splattering onto his quickly paling cheeks.
“I love you too, (Y/n). More than anything in this world. And I always will.” He forced one final smile with the very last of his strength. “I will see you again in Celestia then, my darling, my hero, my (Y/n). Let that be my promise to you.” with those final words, his body fell limp, hands leaving your cheeks as his arms fell to rest loosely at his sides. A scream tore through you as you clutched his limp body desperately against your chest, begging to the heavens for the gods to give him back. Your words fell on deaf ears, your sobs drowned out by the raging battle around you.
Even after the battle had ended with the people of Mondstadt at last driving Khaenri’ah’s forces out of their land, You could not bring yourself to rejoice or celebrate along with the others, instead setting to work on fulfilling your final promise to him. You ensured that Kaeya’s name was remembered as that of a hero to the people of Mondstadt, passed through generations as a story of true strength and loyalty. You filled the hole in your heart by spreading his tale, dedicating your days to ensuring he would forever be remembered in a good light by the people he had given his life to protect.
Even as you neared the end of your own days, you worked tirelessly. And as your time finally came, his final promise to you came true just as yours had for him. You felt no fear or pain as you at last met your own end, only the warmth of a promise fulfilled. The promise that you would indeed meet again in the halls of Celestia.