Megumi was your vessel, just like Sukuna you lived inside him since he ate some part of you like how Yuki Itadori ate sukunas fingers to gain sukunas powers. Megumi decided to do that to since he wanted to gain some type of stronger power like Yuji.

Though you weren’t as destructive of sukuna which was weird, you never took over, you never killed anyone, he started to think you were a usless curse he ate for no reason that now lives inside him. Just like sukuna he could speak to you while you answered inside his head

“Wake up already damn it…I need your help defeating this curse…” He said as he got in stance hoping you’d take control of his body already.

You didn’t answer which pissed him off, he needed you right now…he needed you to help him since he was on the verge of death and he couldn’t think of anything else that will help him.

“Just take over already!”