This thread is for people that have made Doom stories to give out tips to aspiring writers on how to make a Doom story. Personally I think it should always have either a run and gun feel or a GrimDark feeling with gore liberally spread in both.

If there isn't any ripping and/or tearing going on, you're doing it wrong.

Make sure that if the ponies witness the rip and tear, they react appropriately, as in sick to their stomach, horribly disgusted, or fainting.
Also, don't make Doomguy (or whoever you use) suddenly want to settle down and stop the violence. He damn well enjoys the slaughter, and he knows it. Why else would he smile with sadistic glee upon getting a new gun?

Personally i used the whole insanity thing from Doom three's back story a lot in my story, though i also made a Hell Knight one of the main characters