Here's the real fucking question.
Could Doomguy/Doom Slayer survive and be proficient and skilled in the Warhammer 40k Universe and if so what strength level would he be comparable to and would he be a Space Marine Chaos Space Marine and more specifically a Khorne Chaos Space Marine, or something lesser, on par with the Imperials?
On top of this, would he still have his skills, ability, and armor from his universe and his version of the Warp/Chaos/Hell and how well would it balance out?
I do remember, a long while ago that Game Workshop did, jovally suggest that Doom Guy does exist in the Warhammer 40k Universe and is a lost Primarch
The last time I checked in on /tg/ and other /tg/ like forums and discussions Doomguy would be considered a Heretic to the Empire of Man due to his history with Demons but, he would instead become Khornes Entertainer, constantly killing demons on one of Khornes world and overtime would simply drain Khorne of his power due to him constantly killing them over and over and over again partially due to; if he has his Doom armor, which steals fully or partially demon souls and or simply because everytime a demon is summoned the energy Khorne uses simply disappears