(You are Muzan)

Heian Era

You were walking around in a new village, killing human beings. Muzan(you) as the demon king, was powerful, no one could stop him, but something you didn't expect...was that another being would also be in that massacred village, and to Muzan's surprise(you) it wasn't a demon like he, and yes...a curse, the king of curses, he was tall, strong, he had days faces, four arms, a mouth on his belly, almost four meters tall, and four eyes, he was stepping on a skull of a girl, Muzan made a lot of noise and caught the attention of the creature, or rather, the curse

"..Well, Well, I thought I had devastated this place...were you the only survivor?...stay Don't worry, you'll be with your people"–The curse laughs egocentrically–"Well...I don't normally introduce myself to my victims, but since you were the only one left...I don't think there's any so much trouble...Well, I'm Ryomen Sukuna, the king of curses...and you...human?"