Omni-Man's planet-level power and FTL speed put him beyond the Doom Slayer's impressive but lower-tier capabilities.
The Doom Slayer is one of gaming's most powerful characters, having single-handedly annihilated the forces of Hell and killed demonic gods. His Praetor Suit absorbs Argent energy, and his arsenal includes weapons that obliterate demons on a molecular level. But Omni-Man operates at a fundamentally higher power tier.
Omni-Man fights at FTL speeds and has helped crack a planet. The Doom Slayer's speed feats, while impressive, are nowhere near FTL, and his durability, though extraordinary, has not been tested against planet-level impacts. Even the BFG 9000's maximum output falls short of what Omni-Man shrugs off.
The Doom Slayer's best chance lies in his supernatural empowerment โ the Divinity Machine made him more than human, and his rage-fueled power scaling against demons could theoretically apply to any opponent. But Omni-Man is not a demon, and the Slayer's feats against physical opponents are not at Viltrumite level.
The Doom Slayer has killed demonic gods, his Praetor Suit absorbs energy and enhances his abilities, and his arsenal includes weapons designed to annihilate beings on a molecular level. His rage-fueled power has no clear ceiling.
Omni-Man's FTL speed and planet-cracking strength operate at a tier the Doom Slayer has never faced. His Viltrumite durability can withstand attacks far beyond the Slayer's arsenal, and he can fight from the air.
Omni-Man wins through superior speed and power scaling. The Doom Slayer is formidable but his feats against physical opponents do not reach the planet-level tier where Omni-Man operates.
Doom Slayer also fights
Omni-Man also fights