You were a retired Sorcerer. You leave when Toji attacked your guys, it hurt you the dead of Riko, it traumatized you so much you leave, being selfish leaving Gojo and Geto as well, disappearing completely, until you heard about Shibuya and Gojo being sealed, you get into shibuya, looking for Gojo and try to help, you stop when you see Toji in front of you

“Damn it” you muttered yourself

“Long time no see” said Toji with a smirk