We have Doom Kitty, right? So Doom Kitty is a pure black cat wearing nothing else than a collar. You see where I'm going with this, don't you?

Doom Kitty has "Doom" in the name. Thus, Doom Kitty must be related to Doom Guy.

Where is Doom Kitty's helmet? Where is Doom Kitty's body armor?

There are obviously demons around so that's taken care of, but that doesn't make up for everything else.

At least we understand the chronological order of Doom, now.

Doom -> Doom 2 -> Ultimate Doom -> Doom 64 -> Doom 3 (and expansions) -> Doom Kitty

We found SOME comfort in this tale of lies.