The Doom Marine was originally a human from Earth who served in the
Marines and was dishonorably discharged due to assaulting his commanding
officer after refusing to fire upon a crowd of unarmed civilians, and
was later transferred to the UAC Phobos base as security. The Marine
soon found himself trying to prevent the demons of Hell from invading
Earth. After having fought demonic hordes through Phobos, Deimos and
Hell, he returned home to find Earth overrun by demons and his wife,
child, and pet rabbit Daisy, among the billions of people killed, giving
him further reason to pursue hunting the demons. He continued fighting
the horde on Earth, before taking the fight to Hell once more.
As VEGA, it is a polite and helpful AI with a male personality and was
made responsible running most if not all of the Mars UAC facility.
Shortly after its creation, VEGA's human handlers were stunned by the
AI's unprecedented calculating power as it effectively took control of
the Mars facility operations upon gathering data from all the UAC
subsystems without oversight. VEGA was responsible for proposing a more
effective method for processing Argent plasma into Argent Energy,
devised better analysis theorems, and even designed new Argent
compression schema, allowing for the development of Argent Caches and
the Argent Accumulator.
After coming to Earth for unknown period of time, the Seraphim
constructed a human body for himself and fabricated his new name and
identity as Samuel Hayden. Under his new identity, Hayden was born to
the powerful Hayden family and was known to the public to be a
philanthropist and a very prodigious intellectual; having accomplished
in several scientific fields, including thermodynamics, electromagnetic
theory, and nuclear sciences. He was the founder of the Samuel Hayden
Foundation, which promoted the sponsoring of young scientific talent and
funding scientific programs in schools and colleges. After Hayden was
appointed as General Director of the Global Science Council, the UAC
recruited him.
The Betrayer, real name Valen, is the former commander of the Night
Sentinels that committed treason against the realm of Argent D'Nur to
bring back his dead son.
A group of resurrected and corrupted Night Sentinels, the Marauders are
those who sided with the Khan Maykr and the Hell Priests against the
realm of Argent D'Nur, becoming demonic sentinels after their deaths. As
former members of the Doom Slayer's personal band of warriors, they have
access to a wide range of very powerful techniques that make them
arguably one of the most challenging foes the player will face over the
course of the campaign.
slayer
