"Of course he was. Don't worry." The man gives a smile. "I'm the strongest."

Fushiguro's eyes roll so hard it's a wonder they don't screw right off.

"Right-o, then."

He shuts his eyes and...

...Sukuna opens them, markings and claws and four eyes and all. "Cocky sorcerers," he says, and in the blink of an eye he's leapt right at Gojō—

Inches away from the sorcerer, he is stopped by - or to be more accurate, in - something.

And then the cocky sorcerer is behind him, cheerfully ruffling his hair. "It's part of our charm!" he agrees, brightly.

...the fuck?

He whirls around at a speed no one should by rights match and goes for the sorcerer's—eyes, probably, he keeps them covered for a reason.

Nope! The sorcerer is gone, and now behind him again. He cheerfully kicks Sukuna in the butt, smiling irreverently.

"But a cocky sorcerer that can't back it up never lasts long, do they?"

Clearly, someone is having fun.

Okay no this is getting ridiculous. He launches a flurry of attacks—one twentieth of his full power, speed, strength, true, but none but the most exceptional sorcerers should be able to dodge so many in such quick succession so unpredictably—

Apparently this guy is one of the most exceptional sorcerers, because he dodges every single one, and doesn't even make it look hard. Sukuna doesn't so much as graze the man's hair.

There is a pattern to where he's dodging, though. Away from the student, leading his opponent away from the comparatively weaker potential prey.

Yeah so obviously the boy is his next target—he doesn't telegraph it, he's a centuries-old curse, it's easy to not telegraph it and then just swipe that bloody kid's head off—

Nope!

The mentor figure is between Sukuna and the boy in question, and that same moving-in-molasses-but-not feeling stops him again. The boy's head stays where it is.

"That wasn't very sporting, now was it?"

AoE it is. He turns around and then, faster than sound, turns back to them with a punch that should obliterate both where they're standing just with the aftershocks.

It certainly causes some major property damage in front of, around, and behind the sorcerers, but they (and the major structural support holding them both up) are completely unharmed.

"And now you're just throwing a tantrum!"

...he's kind of running out of patience. Fine. Complete structural destruction of the surroundings and—

—and he stumbles in place and puts a hand to his forehead and his markings slowly fade away from his skin and the claws shrink and then Itadori looks up, blinking. "Anime protagonist powers work alright?"

The mysterious mentor figure lets out another laugh. Bits of rubble suspended in air in front of him drop harmlessly to the ground.

"Apparently so! I'm impressed. You really can control it."

Itadori beams. "Now he's trying to convince me to let him out," he says, tapping his temple. "All sorts of threats. Whatever you did really annoyed him."

"That was the point of it. Yet all he can do is rant impotently. And you kept time accurately, too! Very interesting." He walks casually towards Itadori, smiling faintly.

"Yeah I was kind of there but not there? It was weird. I do not really remember what was happening, but I remember remembering, if that makes sense?"

"Some! You," he reaches out to boop Itadori on the nose, "are one special kiddo."

And said special kiddo immediately passes out.

"...what did you do."

And the mysterious mentor figure is there to gently catch him before he hits the ground.

"Is that concern I almost hear? Never fear, my precious student. I just knocked him out. We'll see who's in charge when he wakes up. He could make an excellent vessel."

"...tch. Whatever."

"Heh." Itadori is carefully picked up and slung casually over the sorcerer's shoulder. He retrieves his shopping back from Fushiguro. "Yeah? What do you think we should do with him?"