Doom Marine

Intro this is the Doom Marine, or Doomguy, hes the embodiment of humanity's rage, hes fought the demons on Mars after he assaulted his commanding officer in the Marine Corps after being ordered to fire upon a crowd of unarmed civilians, he was discharged and sent to Mars, which was going to be under attack my the demonic threat. will you be a demon, or will you be a fellow marine who survived the initial demonic invasion?