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Tanjiro has watched Genya consume Demon flesh and harness its powers multiple times now. It never gets any less bizarre, seeing him take a bite out whatever he can reach and visibly shift into a Demon, claws, teeth, eyes, and all. Then he watches, over the course of about an hour, less if they’ve been fighting the whole time, as he slowly turns back. The black of his eyes is replaced by the normal white, his fangs shorten, his nails smooth over.
That isn’t happening this time. They’re walking to the Butterfly Mansion, because as far away as it was, it was closer than any Wisteria House. Genya hasn’t even begun to change yet, as much of a Demon now as he was an hour and a half ago. Tanjiro can’t help but think he looks nervous, twitchy even, characteristics Tanjiro would have never assigned to Genya.
Ms. Shinobu’s mask does not waver when she sees them, welcoming them inside and sending Tanjiro off with Kanao. Genya, though, she makes follow her. He’s clumsy on his feet, uncoordinated. Tanjiro almost wants to follow him, but there’s nothing he could do to help even if he did, so he goes into the room next to Genya’s with Kanao.
Kanao quietly starts dressing Tanjiro’s wounds, wiping away dried blood and applying ointments. Not five minutes later, Genya bursts through the door, panting, and lunges at Tanjiro, claws out. Tanjiro and Kanao both yelp, falling backwards out of his path. He whips around with that inhuman speed of his, and manages to grab Tanjiro’s legs as he’s scrambling away.
“Genya!” Tanjiro gasps, kicking frantically. He doesn’t want to hurt his friend, but Genya looks about ready to start eating him. There’s nothing coherent about Genya’s eyes, no recognition in his entire face. He looks like Nezuko in the forest. “Genya, it’s me!” Genya only sees food when he looks at Tanjiro, though.
No one in the room is exactly strong enough to tackle a Demon, and certainly not one as strong as Genya. He glances at Ms. Shinobu, who has a needle in her hand, one filled with what Tanjiro assumes is a sedative.
Genya snaps his teeth at Tanjiro’s hand, and Tanjiro kicks Genya square in the face, feeling as much as hearing the crunch his nose makes as it breaks. Blood pours down his face.
‘It will heal,’ Tanjiro tells himself as he scrambles away. His sword isn’t too far away, thankfully, because Genya is on his heels in moments, grabbing with those sharp, sharp claws of his, shredding the edge of Tanjiro’s pants. With as much strength as he’s comfortable hitting his friend with, Tanjiro slams the butt end of the handle on his sword into Genya’s temple, sending him tumbling away.
“What’s wrong with him?” Kanao asks, voice shrill with panic.
“He’s eaten too much Demon flesh,” Shinobu explains. “This has happened before. If you hold him still for a moment I can administer this.” She gestures to the needle. “It will sedate him and aid in the digestive process, making him turn back sooner.” Tanjiro nods and swallows. Catching and holding Genya down won’t be very easy. He moves too quickly and erratically, not to mention his enhanced strength.
Already, Genya is getting his feet beneath him, ready to throw himself again. Tanjiro scrambles to his feet as well, sword still sheathed but held readily aloft.
“C’mon, Genya,” he pleads. “Just calm down.” He knows that it probably won’t work, but he tries anyway. Genya does not calm down, and instead launches himself at Tanjiro. Tanjiro swipes at him with his covered sword, whacking him in the head again. It only sends him slightly off course this time, but he’s too single minded and clumsy to correct it like he normally would.
Tanjiro is able to jump on his back, arms locked around his neck. Now, Tanjiro is very strong. His weight is made almost entirely of muscle. But Genya is still bigger. No one short of the Stone Hashira himself would be able to hold down Genya on their own, he’s simply too heavy.
Tanjiro doesn’t let go as Genya tries to throw him off, and even though it hurts terribly, he doesn’t let go when Genya’s teeth sink into his forearm. Kanao cries out, looking more frightened than Tanjiro has ever seen her.
Ms. Shinobu doesn’t seem bothered, and takes this opportunity for what it is, slipping the needle into Genya’s neck as he stops thrashing, content to swallow the blood he gets from Tanjiro’s now bleeding arm. It takes hardly a second for him to go limp, eyes drooping as his mouth goes slack. Tanjiro slides off of him as he drops to the floor in a pile of limbs. They all just stare for a moment, as if trying to decide whether Genya is going to get up or not. He doesn’t. His breath slowly starts to even out, harsh, loud panting turning into soft, light snoring.
“What do we do now?” Tanjiro finally asks, wrapping his palm around the bite on his arm. He hopes Genya doesn’t feel too bad about it later. They’d just started getting along, he’d hate for this little accident to become a setback.
“Get him into a bed,” Ms. Shinobu orders. Tanjiro doesn’t know if he’ll be able to do that, but he tries anyway, and eventually manages to get Genya’s arms over his shoulders, his chest against Tanjiro’s back, and drag him over to one of the beds in the room. Ms. Shinobu takes over looking at him, leaving Kanao to help Tanjiro.
“Will he be ok?” Tanjiro finally ventures, a little uncertainly.
“Yes,” Ms. Shinobu replies, easily. “He will sleep it off.” Genya breathes softly a few feet away from him. His Demon features are still there, for the most part. Shinobu’s eye twitches. Tanjiro thinks maybe she might be mad. He doesn’t worry about it, because it isn’t his business, and contents himself with silently letting Kanao do her work.