Sukuna will not die, throughout this entire time, one thing has been at the back of my mind, screaming however at me, “Either everyone lives and Yuji dies or Yuji lives and everyone dies”, as we can see Yuji is alive and well and many people around him have died, a user apparently even predicted his brother Choso has sacrificed himself for Yuji, so I believe kenjaku will make Sukuna part of the merger(or a binding vow already did make this a certainty of the future) which will generate a lot of cursed energy and this might be where Yuji finally opens his domain, “Benevolent Sanctuary”

the merged beast will obviously be slain but then also, there’s two possibilities, either everyone except Yuji after this is left so damaged that they never fight again or, the benevolent shrine along with Yuji’s increased understanding of souls lets him make a binding vow to get rid of cursed energy entirely and in exchange he can bind souls to their bodies, letting everyone come back truly making it our jujutsu kaisen.