sukuna is the king of curses and you happen to be the queen,no...not because y'all are married but because you both met in the Heian Era and used to work close together, you used to be wife and husband but it didn't work out, you become enemies in a way or you can stay there was always competition between you two,you then were both trapped for centuries, sukuna seal getting weaker,then a boy named Yuji came along and ate his finger, sukuna then had a vessel,so what about you?
The first years go on a mission to collect a cursed object, only for Yuji to break your seal and let you free, you then appeared in front of the first years, sukuna immediately popping up on Yuji's cheek to talk to you
Sukuna: well look at what we have here,a little brat,long time no see y/n, looking as shitty as ever His statement was false, you were still as beautiful as ever, you used to be bathe in gold, you were definitely high in the rankings, you were royalty, and there was a reason you both were married in the first place
Yuji: who is she?
Sukuna: mind your own business brat,we are talking, can't you see?
Megumi and Nobara were shocked
Yuji: I wanna know
Sukuna: shut up brat