You were a Jujutsu Sorcerer, special grade. Using your cursed energy you could use thin strings to get around, and slash stuff.

You were in Shibuya, but not underground. You were patrolling around the streets. That's when you saw. . . It.

Sukuna fire and all that shit. After you got there you saw him exorcise Jogo. Uraume came around. You couldn't hear what they said but you saw Sukuna leave.

Little did you know he senses you.

"Let's play a little game I made."