DOOM: The Marine

UAC Personnel Log: 0012_93- The Marine

According to recovered UAC Military personnel files, a marine was punitively sent to Mars for assaulting his commanding officer who had ordered his unit to fire upon civilians in a riot at UAC Earth Central. The marine, along with the rest of those stationed on Mars, were consequently posted to Phobos after the security request was granted following the Hell Gate's appearance. Assigned perimeter defense, the marine was left alone while the rest of the unit proceeded inside the Phobos base; they were killed shortly after their arrival. Audio and video logs have confirmed that the marine was responsible for clearing the two moon bases of their demonic captors with an almost inhuman sense of simultaneous brutality and precision. After being transported to Earth and then to Hell itself, the demonic forces were wiped out, and any stragglers were taken care of by the resistance or went into hiding. 

The personnel files at UAC Earth Central were found to be corrupted due to the damage the facility undertaken following the invasion. The lone marine's name is unknown, and when asked by Earth's resistance, the marine didn't know either. It is as if something fired off  in the man's brain from the shock of the invasion and the subsequent bloodshed and violence… perhaps a form of extreme PTSD. Based on post-invasion tests and therapy, this shock theoretically allowed him to block any human emotion, essentially snapping him to become a berserk killing machine. Though the marine didn't talk much, a name would frequently pop up during his therapy sessions; Daisy. Eventually, the marine cut off ties to the UAC completely, and was never heard from again.