—they are out on a mountainside that looks like it's been having itself a bad time.

"Sorry about that!" calls Gojo, to the curse. "I'm a teacher, you know. I can't pass up the excellent teaching opportunity you offer!"

"—give a brother a warning!" Pause. "Where, uh, are we?"

In the middle of a shallow lake, it seems, where a weird bipedal curse has been looking for—for—

"Sukuna's vessel," says the curse, dumbly. He's alive?

"I did give you a warning. It doesn't really matter where we are, don't worry about it."

Then, to the curse: "And yes, but it's very interesting that you recognized him immediately."

Seeing the curse's legs half sunk into the water makes Itadori notice that his legs aren't, and he blinks as he lifts and lowers his right foot. "Why aren't we sinking?"

"Planning on using him as a shield, are you?"

"Shhhh," says Gojo, patting Tokan on the head to quiet his many questions. "Pay attention. No, of course not, did you not hear what I just said? He's here for what you're going to do next."

"What.. I'm going to do next? Bringing someone who's just going to slow you down is stupid."

"Aww! Your concern is touching, but I'll be fine. C'mon, I just showed you how you have no chance of hitting me, what are you going to do about it?"

...it's a trap.

It's so obviously a trap.

And Gojō Satoru is literally mocking him about it. "You fucking brat," he screams, the top and sides of his head erupting into enormous jets of lava. "Do not underestimate me!" He brings his hands together, tips of the index fingers and thumbs touching, middle fingers side-by-side, little fingers pulled back. "Domain Expansion."

It extends from behind him, a curtain of pure blackness that surrounds the three of them... and which then sprouts volcanic rock on the ground, walls, and ceiling, with cracks spouting lava everywhere as their only light sources.

  "Coffin of the Iron Mountain!"

"There we go. Thank you!" calls Gojo, brightly. His left hand keeps a firm grip on his student's shoulder. "So! You've already encountered this sort of thing before, Tokan-kun. What is it, and how does this compare to the others you've seen?"

Tōkan is... frozen.

"It's, it's a Domain Expansion. But it's... more like Sukuna's than the other curses'," he says, looking around with saucepan eyes. "I don't know how. But it is."

"Yep! The one made by the detention center's special curse was what you would call an incomplete Domain. Sort of like a messy first pass instead of the fully realized thing. Whereas this," he motions with his free hand, "is the real deal. There's a barrier trapping the both of us inside of it, and any attacks that the owner makes imbued with the Domain around us are guaranteed to hit."

"...shit," Tōkan says mildly.

Most sorcerers would have burnt to ash... just from existing inside his domain. Having this difference in power thrust in his face like that... On his pride as a curse, this is completely unacceptable.

He sends a huge stalactite of stone right at the sorcerers.

"Quite! But there are downsides, and a few ways to counter. The biggest downside is that Domain Expansion is expensive, and imbuing techniques with it so that they always hit is similarly expensive." He reaches out touches the stalactite just before it hits them both; it disintegrates. "And just because the technique hits doesn't mean it hurts. Did you see how it broke against my cursed energy instead of me?"

Nodnodnodnod.

What.

"Now, in theory, you can break out and leave the domain entirely. It's impressed on a barrier, after all, and once you're outside of the area of effect, you're free. I don't really recommend this, though. If someone is powerful and skilled enough to make a complete Domain, their barrier is likely to be quite strong, and most likely reinforced to the inside, to keep its victims inside."

...fuck this dude.

The curse starts sending a barrage of lava at him—here he can just overwhelm his Infinity and kill him—

"But the most effective way to counter another's Domain," he continues, reaching up to remove his blindfold, "is to expand your own." He holds up his right hand, and wraps his index and middle fingers around each other. "Domain Expansion:"

  "I
   N
    F
     I
      N
       I
        T
         E

       V
        O
         I
          D."

Jogo perceives everything. Every mote of dust floating within the barrier. Every breath every person in the Domain takes. The rhythm and sound of their heartbeats. The way space itself twists as the inferior Domain is extinguished. The air pressure around them, the composition of the ground beneath their feet, the precise way the barrier around them has been strengthened, the way light is brought in from the outside and then twisted for this exact light level, the exact configuration of the cursed energy around them—

—And more. Too much. He is an insignificant speck in a grand, uncaring cosmos. He is small, pathetic, and meaningless, in a universe that is bigger than a mind can really comprehend. He is a miniscule, random happenstance, who will exist for the briefest of brief moments, and then be extinguished, and nothing will care. He is a speck, stranded in the infinite, and against it he is nothing at all.

"What happens then is a contest between Domains. Usually the more refined one will dominate the space."

...everything is empty. Or full. At the same time. Their surroundings are crazy, like he's standing in the middle of vacuum or nowhere or everywhere.

The curse, though... is just standing there. Not doing anything. "What happened to him?"