The birth of a hero Edit
Earth is the birthplace of the marine that wiped out entire hordes of Demons that towered above him. These included the Cyberdemon, spider mastermind, Mancubus and Arch-vile. All Demons that are different in size, power, speed and endurance. How a mortal of his own size defeated even one, no one can say. Some say ( many do. ) that he's a Demon that turned on them for unknown reasons and is getting revenge. Some say he is a god himself.
Doom movie Edit
The doom movie's storyline was a backup team of soldiers that are supposed to investigate weird activities on a space research and testing facility on Mars. Then many become infected with a Alien virus that is making everyone undead-like. They are targeting Earth by going through the Arc, a portal to Earth. Then, only two withstand a superpower that gives them a extra set of chromosones. Final battle begins between Grim, a soldier that had lost his parents to a accident on Mars, who is infected by alien DNA which gave him extra power and healed his wounds (good guy) and Sarge, Grim's squad leader, infected with "bad" alien DNA which gave him extra power and is slowly turning him into monster(good guy for 90% of the movie). During fight between these two, Grim stuns Sarge with a heavy blow and pushes him into the Arc (that has 10 seconds until closing), throws a grenade behind hin and saves his sister. Sarge is blown away - along with Mars Arc portal.