Chapter Text
Pain and darkness and brief moments of lucidity filled his senses. Explosions and screams sounded in the distance. A terrible ripping pain was sawing him in two, like an axe splitting down through rotting wood. Medicine rippled over his tongue in waves of bitterness and herbal fragrance. Lights and faces crowded his vision when his eyes could open. That was Aoi, probably. Then Yushiro, looking unimpressed. And then little butterfly sister with the green clips in her braids. A young girl with white hair and startling, purple-gray eyes, one of the Ubuyashiki sisters no doubt. Yushiro again, though more distressed than he’d seemed before. People and hands and hushed conversations and more medicine forced down his throat and injected into his veins.
Below it all, a deep, throbbing ache.
Genya woke with a start in a bed with white sheets and a thin, soft blanket. His core felt battered and mangled, like he’d been ripped apart and put together all out of shape.
Ah, right… He blinked wearily, recalling that he had, in fact, been sliced in half recently.
He was in a room in the hospital wing of the Butterfly Mansion. A lamp burned low and yellow on a table by the door, illuminating a figure in the chair next to him. Silvery-green hair shone in the soft moonlight that filtered in through the curtains.
“You’re awake.” Yushiro said.
Genya looked down. His torso had been wrapped in bandages, and slight redness leaked through in a straight line down his sternum, through his belly, and even down to his crotch. It felt like his head and face were similarly bandaged, and a tacky feeling of drying blood on his forehead and nose all but confirmed it. A small transparent pipe was plugged from Genya’s arm into Yushiro’s, siphoning red blood from the demon into his own body.
Genya took a deep, rattling breath, coughed weakly, then turned to face him.
"What happened?” He croaked, “Did we win?"
"We won. Idiot. You wouldn't be alive otherwise."
Right. That made sense. But even so, hearing that the fight was finally, finally over, made his heart swell with relief.
"Thank f*cking god. I hope you guys gave Muzan hell for me.”
“Oh, we did.” A ghost of a self-satisfied smile came to Yushiro’s face. “He’ll be rotting down there forever.”
“Good.” Genya sighed, then looked over. “So why are you here? Where's Dr. Kochou?"
"Dead."
Genya’s rejoicing heart came to a halting stop.
"...What?"
"She's dead. So are the Snake, Stone, Love, and Mist pillars."
" What?! "
"And about a hundred more slayers, if you can believe it. All dead.”
Genya couldn’t breathe, his throat closed and eyes wide in shock as a terrible despair washed over him.
Gone. They were all gone.
“But so is Muzan.” Yushiro closed his eyes. “That is the price of victory."
Muichiro... He didn't make it after all? And Himejima-sensei... Genya blinked the tears from his eyes before settling on the question he dreaded most.
"And... My brother... The Wind Pillar... Did he..."
"He and the Water Pillar made it, somehow. Lucky bastards. He was actually here not too long ago. He wouldn’t leave your side for the first few days after he recovered enough to walk."
Relief swelled in his chest, though it was still tempered by grief.
"Days? What happened?"
“You’ve been in a coma for about two and a half months. Back in the Infinity Castle we managed to bring you back from the brink of death and stabilize you with my demon flesh, but your condition has not improved much since then. Your body is not reacting as well to my cells as it did with other demons. You can feel it, can’t you?”
“Yes.” Genya nodded after a moment. “You’re different from other demons, aren’t you? The healing is there, but it’s not like it was with demons from Muzan’s blood.”
“Precisely. So you understand that what we did for you was a temporary solution.” Yushiro said, the slits of his eyes flicking a modicum thinner. “Your wounds closed, but they opened again as the weeks went on. A few days ago, you were almost in two pieces again. Kokushibo cut you deep, and with a breathing technique too. As a demon, that’s more or less a death sentence. Your body cannot hold itself together anymore for very long.”
Genya swallowed, the motion sore in his split throat.
“How long do I have?”
“Your condition regressed significantly, beginning about eight weeks after the battle. You’d been unconscious for so long that when your body started to fall apart, they figured it was just the end for you. That’s when I was called in. I’ve been stabilizing you with my blood for the past two days. Your cells are doing the real work, putting you back together, piece by piece.”
“I see.” Genya’s head swam. A sickening, sinking feeling slithered its way into his stomach. His vision throbbed.
“So, after I’m stabilized today, I’ll have another few months to live before I start to die again?”
“Essentially.” Yushiro nodded. “When that time comes, I will come to you again.”
“What are you saying? You’ll just come and feed me your blood, again and again, until I die of old age?”
“Theoretically, my cells could keep you alive forever. I am a demon, after all. You’re more like… half a demon, but still. It could work.”
“I can’t ask you to do that.” Genya shook his head, “That’s too much to ask, I can’t-”
Yushiro slid forward on his chair, his movements fluid as a gossamer-finned eel slithering through water.
“This is your situation. Like it or not, you have two choices. Number one, I come to you every few months or so, and give you a bit of my body so you stay alive. This is a choice I make of my own volition. I know what an inconvenience it will be, and I know this arrangement could continue for much longer than a natural human lifespan. There may come a time when we exist as demons, long after the last of the slayers are dead.”
“A-and my other choice?” Genya asked.
Yushiro didn’t blink.
“Your other choice is death. I will take this tube from my arm, and leave this place. You will live for another few months, then your body will give out on itself and you will split in two again. You will be buried with the other fallen slayers, and due to the secrecy of the corps, your name will be lost to history.”
“Oh.” Genya said in a small voice. “Yes, of course. That makes sense.”
“I will not ask for your choice just yet. But know this. I will leave when the dawn comes. You will not get another chance.”
Dawn… Genya thought, looking out the window. The moon was high, though there looked to be a few more hours of night remaining.
“How did you save me anyway?” Genya asked. “I was dead. My body was flaking away and I saw the afterlife. My family was waiting for me there. How did I come back?”
“Do you remember that drug I gave you, back in the Infinity Castle?”
Genya recalled a terrible heartburn, and waking up to see a purple vial sticking out of his chest. He nodded.
“Lady Tamayo developed that drug to stop a demon from dying. There’s only one dose, so it can only reconstitute a demon once. It would have been disastrous if Muzan got ahold of it of course, so she sent it with me instead, as a failsafe in case I got too injured and couldn’t keep going.”
“That’s very kind of her.” Genya said. Yushiro closed his eyes, head tilted down to the floor.
“She is nothing but kind. She is the most generous and giving person that has ever lived. Anyone that says otherwise will rot in hell with Muzan and the rest of his lot.”
Genya nodded. Yushiro seemed to admire this Tamayo woman a lot. He made a mental note to tread carefully on the subject of his adoration. Yushiro sighed and opened his eyes, staring blankly at the floor.
“I was never going to use the drug on myself though. I was saving it for Lady Tamayo, in case she needed it after her confrontation with Muzan. I don’t care if I die, if it meant I could save her.”
Yushiro looked away.
“I only helped you because it’s what Lady Tamayo would have wanted. By the time I needed to use the drug on her, I was already too late. I figured it was better to save someone’s life than to let it go to waste.”
"I see... So she's gone too..." Genya said softly. "I'm very sorry for your loss. I hear she was an amazing person."
Yushiro was silent for a long moment.
"...She was." He said eventually, still facing away from Genya. "With her gone, I have nothing left but to devote myself to her legacy. Maybe one day I'll step out into the sun and be reunited with her in my next life, but for now, it feels as though she still has work for me to do."
“Work like keeping poor near-dead demon slayers like me alive?” Genya said with a half-hearted chuckle.
Yushiro didn’t laugh.
“I’m sorry,” Genya exhaled wearily, “This is all just… a lot.”
“Yes, I suppose it would be. But regardless, it is a truth you must face. Do not dishonor the dead with your indecision.”
Genya nodded. Outside, crickets chirped in the warm night air, and a distant wind chime tinkled in the courtyard beyond.
“Can you tell me more about them?” Genya asked, bringing his hands close to his chest. “The dead I mean. How did it happen? How did we win?”
“That,” Yushiro sighed, “is a long story. Don’t fall asleep on me now.”
Genya shook his head. There was no way he could miss this.
Yushiro laid out what had been compiled through various accounts about everything that had happened in the Infinity Castle. Of Shinobu’s sacrifice that led to the defeat of Upper Moon Two, of Yushiro’s own struggle against Muzan through Nakime, of the castle crumbling and the demon slayers making their last stand for nearly two hours against Muzan. He told Genya about the brutal battle, the sacrifice of the Pillars, Tanjiro’s final duel against the demon king, and then his brief moment as an all-powerful demon king himself, before Kanao and Nezuko brought him back to humanity.
“So he survived after all that, huh.” Genya said, a slight smile on his mouth. Kamado was tough, he knew, and skilled beyond belief, but still. The relief he felt upon hearing the young man had survived was only parallel to the same news of his brother.
Maybe I’ll get to see Tanjiro again soon. Genya thought, a soft and warm feeling easing away some of the ache in his chest. Tanjiro had the uncanny ability to rain sunshine down on everyone in his presence, and Genya was no exception. He missed that warmth dearly. It would be nice to see the young man again.
“He’s a lucky little brat, that’s for sure.” Yushiro sighed. “Though he didn’t escape unscathed. Hardly anyone did.”
“I understand.” Genya nodded slowly. “In that case, I think I’m ready to make a decision.”
Yushiro leaned forward, though his blank expression betrayed no curiosity one way or the other. Outside, the first traces of pink were bleeding into the violet night sky as dawn came.
“I want to live.” Genya said, breath catching in his throat as tears pricked in his eyes. “I want to see the world we fought for. I want to be with my brother and my friends and live a happy life. Is that selfish of me?”
“That’s all anyone could ask for.” Yushiro bowed his head forward slightly. “I think that’s a noble ambition, Genya.”
Without further warning, the crunch of breaking bone and tearing flesh came as Yushiro ripped his left hand off. He took it by the wrist, holding it so that no blood spilled from the wound, before extending it in offering to Genya.
“Your body digests flesh and bones better than blood. This will restore you to full health faster. Well,” Yushiro tilted his head in scrutiny, “As full health as you can manage in your condition, anyway.”
“You’re serious? Doesn’t that hurt?”
“Of course it does. But I was serious about my offer. I will help you for as long as it takes, just as Lady Tamayo would. Besides,” The bleeding from his wrist sealed off instantly, as new nerves and the beginnings of bones stretched forth from the severed flesh. “Pain doesn’t mean much to us demons, wouldn’t you agree?”
Genya couldn’t argue with that. He’d been slashed and stabbed, hacked limb from limb and riddled with gaping holes, and literally torn in two. It hurt every damn time, but it was a bearable pain as his regeneration took the brunt of it. Losing a hand every now and then would be nothing to a full demon like Yushiro, who could just regrow his missing limbs.
He looked down at the severed hand, then brought it to his mouth. Yushiro didn’t look away as Genya’s strong teeth crunched through his bones and pierced through his flesh, didn’t even wince when the fingernails cracked open between Genya's incisors.
f*ck, this is so awkward… Genya thought, avoiding the demon’s unblinking eye as he willed himself to eat the hand faster.
As always, demon flesh was unpleasant. But Yushiro’s was unpleasant in a different way, a more tolerable kind of unpleasantness that left Genya not wholly revolted as he usually was. The demonic transformation he underwent next was less unpleasant than usual too. In the past, it was a painful and grueling affair, of sharpening teeth and expanding bones and an uncomfortable buzzing and squishing sensation in his eyes as they adapted to perfect night vision. All those aspects of his transformation were here now, though less so, as if Yushiro’s more benevolent blood brought out a less-extreme transformation than the demons that served Muzan had.
A puckering sensation went up and down the length of his body, through the thick scar that circled him now like a vertical ring. The wound closed completely. Genya breathed a sigh of relief as a sting of pain wore away. He hadn’t even realized he was in that much pain to begin with. He supposed he’d gotten used to it during his time unconscious.
“You are a curiosity, aren’t you?” Yushiro said, surveying him with a slight squint. “That is interesting. Now it makes sense why Lady Tamayo and the butterfly woman talked so much about you.”
He rose and dusted himself off, then plucked the blood transfering tube from his and Genya’s inner forearms. Genya blinked, confused.
“They talked about me?”
“All the time. By studying your cells, they were able to understand a lot about demon transformation and reversal. It’s how they were able to develop the drug to turn demons back into humans, and was helpful in developing the other drugs used against Muzan as well. You helped a lot more than you realized.”
“I had no idea…” Genya breathed. He supposed Shinobu had been asking him for more samples in the days before the final battle, but he’d brushed it off as just medical screenings. He hadn’t known his bits of teeth and hair and blood were that important.
“Yushiro-san, thank you for helping me with this. I don’t know how I can repay you.”
“You can repay me by living.” Yushiro said, a gentle light in his gaze. “Life is a gift that too many foolish humans squander. Don’t count yourself among them.”
Genya nodded, a broad smile on his face.
“Well, I suppose I should take my leave now. After all, you have a visitor.”
“Visitor? What-”
Genya looked over to the door, and jerked in fright. He hadn’t even heard it open. Lit by the yellow of the lamp was the only man who possibly had more scar on his body than Genya did, his shock of white hair framing his wild eyes as his frenzied gaze focused on Genya.
Sanemi Shinazugawa stepped into the room.
