It seems that Ultron prefers to use his biological manipulation so don’t think Gogeta can get enough damage off before being reality warped or turned into a slave. How high can Gogeta go into kaio ken?
Biological manipulation takes various hours to work as seen in the story mode, even after being exposed, all the fighters have time to fight various opponents, so i think Gogeta being brainwashed is just out of the picture.
And Dante/Captain Marvel also did not seem to use anything aside of puunches to take down Ultron Omega, which is implied to be more powerful than base, since X used 4 stones and the power from the rest of thhe heroes to finish off Omega, you can maybe asume Omega is at leastt 2 or 3 times baseline 2-C if all stones are the same in power.
Regardless, Ultron Sigma's 2-C is because he fused two universes together, so he should also be around baseline. Even the most basic kaiohken or Gogeta being at least 2 times stronger than Broly should seal the deal.
Gogeta seems to be a better fighter, and he can also get the AP and Durability advantage with Kaioken (if he'll use it). Biological Manipulation is a problem, but if it indeed takes hours to be applied then it doesn't matter much.
Leon Help4 wrote: The biological manip is faster if applied directly, which would never happen as in the situation it was used in, Thor was already beat up, defeated and restrained directly in front of Ultron Sigma.
Indirect exposure (aka. the entire cast) lasted long enough for the fighters to have multiple fights and took several hours to start to take effect.
How much faster would it be applied? Since Gogeta won't just stand there waiting for it to affect him. If it would be applied fast enough, then Gogeta could win by higher skill and Kaioken before it will affect him
Hell, that is also a deal breaker for Ultron since he either has to inflict biological manip directly at Gogeta at close range or use a gas bomb like he did with Wakanda (the indirect exposure that takes hours).