In the comics, Rom is more than a simple cyborg, being originally from a utopian society on a planet called Galador. The series details Rom's defeat of an invading alien race known as Dire Wraiths, and the continuation of their battle on Earth and other planets. Unlike the technologically advanced Galadorian civilization, the Dire Wraiths rely primarily on dark magic and their power to change their appearance.
Some years before Rom's arrival on Earth, Galador is threatened by a fleet of ships manned by the Dire Wraiths. Galador's ruler, the Prime Director, calls for volunteers to be transformed into cyborg warriors called 'Spaceknights', so that they can defend the planet from the invaders. The volunteers are promised that their "humanity" (that is, the body parts that would be removed to accommodate the bionic armor) would be preserved and restored to them after the danger was over. Rom was the first to volunteer, and was transformed into a large, silver humanoid that at first glance appeared to be totally robotic. Rom was given Galador's greatest weapon - the Neutralizer - which on one setting could banish the Wraiths into the dimension known as Limbo forever. Inspired by his example, a total of 1,000 Galadorians volunteered and were transformed into Spaceknights, each with his or her own unique armor, powers and code names.
The Spaceknights succeeded in stopping the Wraith invasion, although Rom decided to follow the remnants of the fleet back to their home planet – Wraithworld – which orbited a black sun. The Wraiths panicked, and after a futile counter-attack abandoned the planet and scattered throughout space. Unable to stop Rom, the Wraiths successfully used their sorcery to trick him into allowing their escape. Rom now felt responsible for spreading the Wraiths’ evil across the universe, and swore he would not reclaim his humanity until all Dire Wraiths had been vanquished. His fellow Spaceknights, including comrades Starshine and Terminator, swore the same oath and left Galador.
Rom arrives on Earth 200 years later, and it is at this point that the Rom series begins. Landing near the fictional town of Clairton, in West Virginia, United States, Rom encounters a young woman named Brandy Clark. After seeing Rom deal with the Wraiths firsthand, Brandy comes to understand his mission and helps to hide Rom from prying eyes. This becomes necessary once Rom uses the Neutralizer in public, as witnesses only see a "killer robot" disintegrating innocents - they do not realize that Rom is in fact banishing Wraiths in human form. In time Brandy's boyfriend, Steve Jackson, helps Rom in his mission, although when Brandy began to fall in love with the noble Rom her relationship with Steve was strained.
During his time on Earth, Rom fights and banishes thousands of Wraiths. The increasingly desperate Wraiths create new foes for Rom, such as Firefall - a fusion of human and Spaceknight; the sorcerous Hellhounds; and robotic Watchwraiths. Two of Rom's greatest foes are the aptly named Hybrid (a hideous result of a union between Wraith and human), and Mentus (a suit of Spaceknight armor occupied by the dark side of the Prime Director's psyche). Many other opponents were more traditional and hailed from the Marvel Universe proper, such as the Mad Thinker, the Space Phantom, and Galactus and his herald Terrax. He encountered such heroes as the X-Men, Power Man and Iron Fist, the Fantastic Four, Nova, the Thing, and the Hulk. Rom was one of the many heroes transported into an arena in space for the Contest of Champions though he was not chosen to participate.
At one stage, Rom's war against the Wraiths takes a turn for the worse - a new breed of Wraith appeared on Earth, and appeared to be far deadlier than the first variety. It is later revealed that these are female Wraiths, who rely on sorcery, as opposed to the weaker males who placed their faith in science. Unlike the males, the female Wraiths chose not to act in secrecy and openly attack Clairton while Rom is away, killing everyone (including Steve Jackson and superhero ally the Torpedo) with the exception of Brandy Clark. Furthermore, they attack S.H.I.E.L.D.'s mobile headquarters, the Helicarrier, which gave Earth authorities clear evidence of the existence and threat of the Dire Wraiths. The Dire Wraiths came into conflict with the Avengers and the X-Men as well. Rom manages to banish all Dire Wraiths on Earth to Limbo with the aid of his super-powered allies and members of the U.S. military.
Rom leaves Earth soon after the battle and returns to Galador. Unknown to Rom, Brandy had accidentally met the entity called the Beyonder, and asked him to transport her to Galador. The Beyonder complied and Brandy found herself on Galador, now a war-torn world occupied by a new generation of cyborg-Spaceknights. Created to defend Galador in the absence of the first Spaceknights, this next generation of cyborgs became corrupted by their power, and feeling superior to normal Galadorians, massacred the entire race. In an act of sheer spite the new Spaceknights destroyed the frozen remains of the originals. Rom arrived too late and could only save Brandy. Enraged, Rom summoned the original Spaceknights and together they destroyed the traitors. Rom then made a surprising discovery - his original humanity persisted within the entombed body of Terminator. Reclaiming it, Rom became human again and finally admitted his love for Brandy. The two chose to remain on Galador, with the intent of repopulating the planet. The remaining Spaceknights, their humanity now lost, set out to explore the universe, except for a few others that remained on Galador to protect Rom and Brandy.