Mahoraga take away all the techniques from Sukuna, it was because of sukuna's adaptation that he got into void. Sukuna without mahoraga just wins the domain battle and that's the end. In the form of haian, it won't take much trouble. Sukuna, even with 19 fingers and in megumi's body, could break the gojo domain from the inside, but due to adaptation, he was deprived of techniques. So without mahoraga, everything ends with Sukuna winning domain battle