"Don't look inside me without my permission," says Sukuna. "I hate it when people do that."
...he's not dead? Or maybe he is, and this is hell.
A spine, and ribs, enormous and extending forwards and backwards into unseen distances. The floor is covered with - red liquid, looks and feels like blood, but his shoes aren't getting stained. Magic blood.
And Ryōmen Sukuna, king of curses, wearing his body, with the various markings visible where the long, loose kimono he's wearing isn't covering his skin (maybe the reason he keeps ripping Itadori's shirt off is just because he prefers looser clothing, rather than really enjoying being shirtless per se), is sitting atop a throne of bones which itself is the appex of a mountain of Yet More Bones, the centerpiece of this location.
"I have to give it to you," Itadori says, looking up at the curse, "this place is really aesthetic."
Sukuna laughs and leans forward on his throne, resting his elbows on his knees and his chin on his interlaced fingers. "Figure it out, did you?"
"We are in your Innate Domain. And I am not... completely dead? No reason for you to be wearing my body otherwise."
He laughs again and leans back onto his throne, clapping slowly as he crosses his left leg over his right one. "Right in one! Maybe you're more interesting than I gave you credit for."
Itadori shrugs. "I am one of the protagonists of this anime, after all. And... I figure I am not the boring kind where the viewer's meant to just generically project themself onto me, I have a proper personality and all."
"You know," says Sukuna, tilting his head a bit and looking up at the - not exactly ceiling. Bone cage? "I was expecting you to have attacked me by now or something."
"You," he says, pointing at Sukuna, "are about to offer me some conditions to heal my heart and bring me back to life. And then we will haggle over them but I will inevitably accept them, and the plot can continue."
"Am I so predictable?" asks the king of curses, leaping from his throne and landing on the water in front of Itadori. He folds his arms behind his back and starts slowly making a circle around him. "You seem to think we're in a story. It almost makes me want to withdraw the offer I haven't even made yet."
"But you will not, because you have a huge crush on Fushiguro and Hayashi. Do not deny it, I saw it all. You're interested in seeing where they go, next. Aren't you?"
"Perceptive! I might be taking an interest in you, too."
"Say, four arms, four eyes, who knows how many mouths - do you also have...?" and he lowers his right hand to his groin area, two fingers extended out.
Sukuna laughs, again. "Wouldn't you like to know?"
"Well, I mean, I figure, we're in your Innate Domain for a while anyway, maybe you could have your way with me and I would not even be dead on the other side of it so whatever deal we gotta make can still go through."
He sighs and shakes his head, still pacing a circle. "This is nowhere near as fun if you're willing."
"Are you saying Ryōmen Sukuna, king of curses, isn't creative enough to make me regret my choices even in his own Innate Domain?"
Faster than the eyes can track, Sukuna slaps Itadori hard enough to send him crashing onto one of the ribs surrounding them. "Mind your tongue, brat."
Itadori slides down from the rib onto the water but starts laughing, wiping some blood from his lips with the back of his sleeve as he does. "Is that the best you can do? I guess I really am disappointed, four arms and two dicks and you can't even make me scream."
Sukuna is in front of Itadori in a fraction of a second, but rather than hitting Itadori some more, he narrows his eyes and leans forward. "You find this enjoyable, don't you?" He reaches a hand and grabs Itadori by the crotch. "You actually enjoy this, you disgusting little brat."
He doesn't quite manage to hold back the whimper of - pain, pleasure, who knows - when Sukuna squeezes him there. "A sadistic king of curses possessing a masochistic boy with not a drop of sense in his head," he says, nodding. "Yes, Sukuna-sama. Maybe you could rip my cock off? That would make me scream, alright, and probably hurt in a bad way. And I would still survive, wouldn't I? I would make... so many pretty noises for you..." He leans closer to the curse's face. "You could fuck me with those two dicks, I bet they're huge, I bet you could fuck me in the ass and in the hole you just tore in my groin -"
Sukuna slaps Itadori again, hard enough Itadori's neck actually cracks from the force of the blow before he even lands and falls limply on the water. "You're boring me," he says, frowning.
It takes him a couple of seconds, but eventually he laughs, again. "Oh, fuck, that hurt a lot. And you broke my spine, you asshole, I can't even feel my dick anymore."
Sukuna steps over to Itadori, impossibly quickly again, and with a snap of his fingers Itadori's spine is healed, only for him to be able to feel the pain of Sukuna's stepping onto his crotch, but even more importantly the pain of the claws on the curse's right hand impaling him on the left shoulder.
"Nnngh, yes, Sukuna-sama, more-!"
Ow ow ow that hurts a lot it's hot but it hurts a fuckton holy shit -
He leans forward, close to Itadori's face, and says, in a low voice: "My conditions: when I chant 'extension', you'll hand over your body for one minute; and you will forget you made this pact with me."
"Magic pact, is this? One you cannot," he groans with the pain of trying to talk while impaled, "break?"