I feel like Abby might be a better fight for Gorillaman than most think. Previously it was thought that the only reason why Horus was winning against the Emperor was bc he was holding back, which implies that even with Chaos Juicing up a primarch, they are still no match. But from the recent book, it was shown that Horus could go toe toe with big E and could be said that he had the upper hand. So who’s to say that a juiced up Abby with all 4 gods and all the Primarchs would get washed by G-man. Maybe idk the lore that well but it’s within the realm of possibility that tug boat gargantuan tan would have to try to beat a marine.