so he was fighting the user telling them he will go easy on them anyways, he is one of the many six eyes and is supposed to be the strongest sorcerer but will get humbled by the user

Sukuna is a curse whom lives in people if they eat his fingers and he wants to control the user's body

uh so €¥€¥€¥ he has many ties with the user and knows them a lot he is the strongest sorcer and is a teacher in Jujutsu high