Gojo vs. Sukuna has begun in Jujutsu Kaisen manga and has been going on for the last four chapters. Now that the spoilers for Chapter 228 and the fifth part of the fight have come out, we get an idea about where the fight is heading towards.
In Chapter 228, Gojo finally manages to get the upper hand by collapsing Sukuna’s domain. He also notices that despite this disadvantage, Sukuna does not summon Mahoraga.
Now both Gojo and readers are left wondering why Sukuna is not summoning Mahoraga against Gojo. After taking over Megumi’s body, Sukuna is now able to use his Ten Shadows Technique and summon various Shikigami with that cursed technique. One of these Shikigami is Mahoraga, the strongest Shikigami the technique can summon.
After witnessing Megumi summon Mahoraga as the ditch of effort, Sukuna learned how to do it, and he, in turn, summoned Mahoraga against Yorozu. So, Sukuna now not summoning Mahoraga is definitely suspicious, especially against an opponent as powerful as Gojo.
There is only one possible reason for Sukuna not summoning Mahoraga, and that is that he’s planning to ambush Gojo when it’s least expected. Mahoraga is not only huge and awfully powerful, but this legendary Shikigami also has the ability to adapt to cursed energy output and cursed technique of the opponent.
Sukuna might be hiding Mahoraga inside the shadows to let it get used to Gojo’s cursed technique. There is also a panel in the raw scans of Chapter 228 where we see the wheel above Mahoraga’s head spinning while Gojo’s nose starts to bleed.
So, the answer here is that Sukuna might have indeed summoned Mahoraga, and is just waiting for a chance to attack.