Goku's universal-level combat power exists in a tier that even the Doom Slayer's demon-slaying arsenal cannot reach.
The Doom Slayer is one of the most feared beings in gaming lore. Blessed by the Seraphim with supernatural power, he's fought through Hell for eons, killed the Icon of Sin (whose presence corrupts reality), slain Titans with the Crucible blade, and defeated the Dark Lord of Hell. His rage is infinite, his arsenal is devastating, and he has never been defeated in combat.
But Goku fights at a scale that the DOOM universe simply doesn't operate at. Goku's punch clashes with Beerus nearly destroyed Universe 7 โ an infinite void containing countless galaxies. That was in his weakest Super Saiyan God form. Mastered Ultra Instinct Goku is immeasurably beyond that, fighting opponents who threaten the multiverse itself.
The Doom Slayer's best feats โ killing the Icon of Sin, defeating the Dark Lord โ are impressive but exist at planetary-to-dimensional scale within DOOM's cosmology. Goku surpassed planetary in the Saiyan Saga. The speed gap is equally severe โ Goku was faster than light by the Frieza Saga, while the Doom Slayer, for all his power, can still be hit by relatively slow-moving projectiles in gameplay and cutscenes.
The Doom Slayer's lore says he's imbued with power to slay any demon. But Goku isn't a demon โ he's a Saiyan who operates under Dragon Ball physics where punches carry universal energy. The Doom Slayer's kit is purpose-built for Hell's demons, and while it's devastatingly effective in that context, it doesn't scale to universe-busting opponents.
The Doom Slayer has fought for eons without tiring, blessed with power that lets him slay any demon in existence. His Crucible blade can kill Titans, and the BFG-9000 fires concentrated argent energy. He defeated the Dark Lord โ literally God of the DOOM universe โ in single combat. His power is defined by being sufficient for any threat, which could theoretically apply to Goku.
Goku's combat power threatens entire universes, and Ultra Instinct gives him autonomous dodge that makes him functionally untouchable. A casual Kamehameha from current Goku carries more energy than any weapon in the DOOM arsenal. Goku's speed transcends the concept of light, and his durability has tanked attacks from universe-level beings. The scaling gap is simply too vast.
Goku wins overwhelmingly. The Doom Slayer is gaming's ultimate power fantasy, but Dragon Ball's universe-and-beyond power scaling creates a gap that cannot be bridged by lore statements or demon-slaying feats. Goku would likely enjoy the fight, but it would be over the moment he got serious.
Doom Slayer also fights
Goku also fights