Omni-Man from the latest animated series called Invincible, takes on members of the S-Class from the hit anime series One Punch Man. Omni-Man is a Viltrumite, a warrior race with tremendous power that is almost equivilant to Superman. The race of Viltrumites also have a similar story when compared to Saiyans from Dragon Ball Z.
On the side of the S-Class (from One Punch Man), the fighters consist of Zombie Man, Genos, Drive Knight, Dark Shine, Atomic Samurai, Flashy Flash, Tatsumaki, Akai Mask, Puri Prisoner, Tank Top Master, Pig God, Watch Dog Man, Child Emperor, and Bang. All are elite fighters with amazing power and ability.
On the animated show Invincible, we get a glance on what a “bloodlusted Superman”, who doesn’t hold back, would look like. In this fanimation battle, it takes the united power of the S-Class to kill Omni-Man. The fact that their were actual casualties show how serious of a threat Omni-Man was. Had Saitama stepped in from the very beginning, maybe the result of this battle would had been decided much earlier.
Omni-Man vs S-Class Fanimation by AniMatt.