After Kaori, in this current generation, Kenjaku implanted his brain into one of the strongest sorcerers of this era, Geto Suguru. After the battle withOkkotsu Yuta, Geto was killed by his best friend Gojo, as mentioned in the last words of Geto. As Geto’s body wasn’t cremated, Ken...
In terms of where the story of JuJutsu Kaisen is in the anime, we don’t know too much about the back story of Sukuna. The most information that we’re given about him comes from the interrogation that good old Gojo conducts on Itadori after they subdue him post eating the finger. Gojo...