I think these Sukuna battles are only for buying time. I maintain that Sukuna's only real weakness is his soul. He was uber defensive when Mahito touched it. Attacking the soul is Nobara's specialty. I still don't buy that Gojo is dead. Face it, Gojo is the real protagonist for JJK. He needs to come back or pass the torch in some way. One key is Sukuna's missing finger. Gojo has done something with it. The finger is the key for Gojo coming back or for Nobara throwing Sukuna off his game enough so others can seal the deal.