Master Levels for Doom … Doom slayer patch, Doom patch, Doom marine, DM1-5, Doom guy, doom slayer rune, Doom eternal, Doom slayer symbol, gift for him, gift under 10. Waterproofed print! Old Doomguy (often referred to as Doomguy or the Doom Marine) is the protagonist and player character in the upcoming mod DOOM: Reawakened.