1. First, Sukuna knows/recognizes/understands Yuji and what he is and where—rather who—he comes from

I guess since Yuji was his vessel he wasn’t able to get a full understanding of Yuji’s lineage and him being Choso’s little bro as a cursed womb painting, but now that he’s out of Yuji, he can see it all—and whew he wasn’t quite ready for it. Right before this, Sukuna was kinda puzzled by Yuji’s strength…and then he realized. He recognized that Yuji is potentially a product of what I affectionally call Kenjaku’s asshole era (though he has a couple of those) and knew Kenjaku has something to do with Yuji. Which brings me to the second thing

2. He, Ryomen, the ‘King of Curses’, Sukuna, is disgusted (or at least grossed out) by Kenjaku’s actions

Apparently Sukuna has a line that even he won’t cross and Kenjaku crossed it (and apparently crosses it frequently since he said grossest things, which implies Kenny does gross shit all the time or at least on a regular enough basis that he knows the horrible history). Sukuna maybe said it with a touch of admiration, but mostly it read in a way that was like, as messed up as he is himself, there’s things even he won’t do, and Kenjaku is the type to do them—

Which is wild to me, because you have to do some really messed up things for the King of Curses to say you do gross things. And we know Kenjaku is bad and he’s done messed up and gross things but like dude is apparently even worse than what we know, and has done things so incredibly awful and obscene and horrible that even Sukuna is like yikes.

I’m rambling but whether his comment is in admiration or disgust or a bit of both, it’s clear from Sukuna’s words that Kenjaku is worse than him. Which, while I’m comparing Sukuna and Kenjaku, brings me to the third thing.

3. Megumi is pulling a Suguru and is taking back control of his body

Kenjaku may be using Suguru as a vessel, but during Shibuya he tried to regain control for a brief second after Satoru tried speaking directly to Suguru (remember the whole, you’re just gonna let him use you like that comment and Suguru’s movement against Kenjaku’s wishes?). The same is happening with Sukuna to Megumi, except since Megumi is still alive he’s fighting back harder than Suguru’s residuals. And he’s fighting so intensely that he’s impacting his energy output so he can’t attack Yuji as hard as he wants.

Megumi said ‘not today’ and Sukuna, for what it’s worth, kinda doesn’t seem too mad about it. And I wouldn’t be surprised if he was expecting him to fight back. After all, he’s against Megumi before and knows what he’s capable of (kid’s a Zen’in after all) and what he’s like when he’s in fighting for his friends, but especially Yuji.

Sukuna when someone enters his domain:

Elias van Nijmegen