Gojo is gonna beat Sukuna and the moment he does and everyone is about to take a deep breath and feel excited about the outcome Kenjaku is just going to finish Gojo off. We'll get a similar situation to when Toji killed Amanai; maybe Gojo will be conscious of his imminent death and will say "it was great" or "I'll let you guys finish this" with a huge smile on his face as he gets his head cleanly severed.
I need to spoil myself I can't bear waiting