I played KH3 and got a lot of Vanitas feelings, and this is how I express them :D No spoilers here, though, don't worry. Just a lot of a gross boy being extra gross~

Warnings: Guro, Blood, Knifeplay, Cannibalism, Non-consensual Cannibalism, Tortue, Pseudo-Incest

Vanitas knows one thing more than anything else in life: Ventus belongs with him. They have to be together: forever part of each other after being pulled apart so much it hurts.

The edges between you and I should be erased, Brother-
Vanitas-

He's sure Ventus will agree- despite their constant arguments, he has to know, deep down, that this is best for both of them. They're going to be together in the deepest way, intertwined so that no one can separate them ever again.

It's going to feel so good-
No, I don't-
Shhhh-

Vanitas has never cut anyone up so precisely before, but he's giddy with excitement as the knife slides into soft, pale flesh with ease and blood pools up immediately. He has to contain himself, slow down a bit, so that he can carve each point of the star. For a second, he thinks he feels Ventus struggle, but why would he? He's doing this for them! And he's including something just for Ven, too, since he's always been a big sap.

He finishes without any further hesitations, ignoring the desperate sounds Ventus is making around his gag. Vanitas wants to rip the chunk of flesh out of his arm and devour it right now, but he's got a plan. It's a special day for both of them and now that he's got Ventus trapped under him, he doesn't have to rush things- as much as he wants to.

Vanit-
Shhh shhh, shhhh Brother, what's wrong? This is such a delicious way to be together-

Having a piece of Ventus so close is exhilarating, so much so that it almost distracts him from finishing the task at hand. Vanitas pulls himself out of it enough to turn the knife on himself, cutting out a matching chunk from his arm. It's not perfect but the spirit of it is there, and now it's time.

As soon as he removes the gag, the complaining starts. Vanitas rolls his eyes; he should have expected this. Ventus never appreciates the things he does for them, but that changes today! He digs the handle of the knife into the gaping wound on Ven's arm until his brother screams. That stops the whining. He's still shaking, but so is Vanitas- from glee, from the thrill of watching their blood mix together as it gathers on the floor them...it's enough to renew his fervor.

He crouches down to Ventus's level and pauses. "There's this rumor I heard of that sounds pretty stupid, but you like that kind of sappy shit. If you share this fruit with someone, your destinies are tied together, which sounds like a load of crap to me!"

Ventus lets out another sob, probably because he's disappointed in Vanitas's attitude about the stupid fruit story. Whatever, he's doing this for them, and he's putting up with his brother's softer side in the process. He should be grateful.

"So I didn't go get fruit, because what's the point? It's just fruit! This works just as well!"

"Why-" Ventus tries to say, but Vanitas interrupts him.

"For you, Brother, and for us! Don't you want to always be inside of each other?" he asks, and doesn't bother waiting for an answer- Ventus never quite understands the things he does for them. Vanitas shoves the star shaped lump of his flesh into Ventus's mouth and clamps his hand over it, just in case he has some stupid ideas about refusing his offering. He can feel Ventus gagging, desperately trying to reject the offer, but there's no use.

Vanitas drops the knife and uses his now free hand to rip the flesh from Ven's arm. He wants to savor every second of tasting his brother - it's the most intimate fucking thing they could do together, short of crawling inside of each other's skin - but the first taste of blood on his tongue, the sweet tang of Ventus drives him crazy. He doesn't have to wait; he can have all of Ventus right now, and it's too tempting to wait any longer.

It goes down rough, but he knows it's the struggle that makes things worth it sometimes, and Vanitas groans as he swallows. Ventus is still sobbing underneath him and everything is a messy vision in red around them, and he feels such a rush from it.

He glances down and grins- his brother swallowed his share, too! Vanitas removes his hand and watches Ventus choke some, but he's not worried. Like he could possibly separate them now. No, he and Ventus are closer than ever, a piece of each other forever inside the other, and Vanitas gasps with laughter as he thinks about it. This is so good.

"I could eat you for days, brother," he says, licking some blood from his fingers. Ventus's eyes widen, bright blue and shining with tears, and Vanitas shrugs. "But then I might run out, and what's the point then? I need some of you left for when we finally become one."

Ventus tries to say something, but it just comes out as an unintelligible sob. Vanitas chuckles, roughly tousling his brother's hair with his bloody fingers and twirling the knife in his other hand. This bond will last them until they're truly reunited.

You're disgusting-
You're mine.