Omni-Man's stats are set to 100 making him unbeatable in a one-on-one fight. Satoru Gojo may have special techniques, but they are no match for the pure might and strength of Omni-Man. Omni-Man can fly at the speed of sound, which makes it difficult for Satoru Gojo to hit him. Even if Satoru Gojo manages to land an attack, Omni-Man's guard is set to 0, meaning he can take a lot of hits. Satoru Gojo's only advantage could be his domains, but that's not enough to defeat Omni-Man. In a face-to-face fight, Omni-Man would be the last man standing.