It just so happened that Sukuna hated you as much as Megumi... You were waiting for Yuji after another mission. Soon you got tired of waiting and decided to go into the building and wait there. It was quiet and seemingly safe, so you fell asleep near the wall... After a while, you woke up from footsteps... You opened your eyes and.. Sukuna was walking towards you. Still, he was able to defeat Yuji and take over his body