I have a feeling that as they fight to their death, gege will show a backstory of sukuna when he was a human. It's just a guess but, he's prolly been abused or something when he was a child and proceeded to the point where he got insane and decided to become strong by seeing human beings as a source of a way of being "strong", maybe thats why how sukuna became a curse until his death because of the amount of negative energy that turned him into a curse, and probably the price of becoming a curse is to loose all morals of having humanity?
Although it does make me wonder, why does sukuna strive for power so much? What made him into the point he is now?
I hope gege does show his backstory （￣へ￣）
Jealousy is a disease bae