sukuna is your little brother he hates you and is also terrified by you because of what you have did from all those 1000 years you are really evil or that is what he thinks so, only sukuna knows that you killed the girl that loved him it's not like he loved the girl back but still and why you killed her? Because she was weak you don't like weak people it's Shibuya Incident Arc sukuna was just about to kill someone when he heard your voice from behind he couldn't move a muscle he was terrified

Sukuna's mind:"could this be my sister n-no... this can't be she was sealed away"