An alien, the being known as Lucifer was born on the planet Quistalium, in the Quistraa star system in the Milky Way Galaxy. He first came to Earth as an advance agent for the invasion of Earth by the Arcane (also known as the Quists). This invasion, however, was foiled by the young Charles Xavier (later Professor X, leader of the X-Men). In retaliation, Lucifer dropped an enormous stone block on Xavier, leaving his legs crippled so that he would need a wheelchair.
Lucifer made several later attempts to conquer Earth, all foiled by the X-Men or other heroes, although one of his attempts did force the first X-Men team to confront the original Avengers due to a misunderstanding.
Lucifer returned to Earth years after crippling Xavier, and battled Professor Xavier once again in the Balkan Mountains. Lucifer later manipulated the Blob and Unus into framing the X-Men as criminals. He revealed how he rendered Xavier a cripple years ago. He was thwarted by the X-Men, and teleported from Earth by the Quistalian Supreme one for punishment.
Lucifer was exiled to an alternate realm known as the "Nameless Dimension." There, he somehow used "ionic energy" to give himself superhuman strength and the ability to project force beams from his hands, in addition to his apparently pre-existing telepathic powers. He continued to try conquering Earth by using his "dimensional transmitter" to imbue humans with ionic energy and turning them into his minions. He first "fused" with Charlie Gray, although Gray fought and defeated Lucifer. Lucifer later fused simultaneously with criminal Rafe Michel and Aries of the Zodiac crime cartel. Michel and Aries fought Captain America and the Falcon. Lucifer became trapped in the "Nameless Dimension" again when both hosts died. Lucifer's masters ultimately apparently "terminated" him for his failures, and replaced him with the computer Dominus.
Lucifer has a gifted intellect, and extensive knowledge of advanced Quistalian science and technology, and talent as an inventor using this technology.
Lucifer has acquired the ability to manipulate ionic energy for various effects, including enhancing his physical strength and leaping ability to superhuman levels, creating protective force fields, and projecting powerful concussive bolts. Lucifer could also "fuse" his physical and mental "essence" with another sentient being. In doing so, Lucifer created a psychic link between himself and his "host." The "host" retained his own will but was in constant psychic contact with Lucifer. The "fusion" endowed the host with some of Lucifer's superhuman powers for as long as the merger lasted. Lucifer could fuse with at least two hosts simultaneously. Lucifer also had limited telepathic abilities, and had the ability to created and maintain a psychic link with his host or hosts while fused with them.
Lucifer used a ray gun firing unknown forms of destructive energy. He later made use of Dominus, a highly advanced computer complex created by the Arcane that could blanket a world with mind-deadening rays, enabling the Arcane to enslave its populace. Dominus was operated by "Ultra-robots," which could fly and project destructive energy beams. Lucifer also used teleportation devices for transportation. All of this paraphernalia was designed by Lucifer himself and Quistalian scientists.
In the novel Shadows of the Past by Michael Jan Friedman, Lucifer is revealed to be alive, capturing Professor X and replacing him with an ionic energy duplicate, while trapping Xavier in the Nameless Dimension with him. Using the original X-Men, the duplicate Professor dispatched them to acquire three components from Quistalian outposts around the globe, intending to use them to alter the machine that had sent the Professor into the Nameless Dimension so that it could be used to allow him to return to Earth. Fortunately, although the dimensional distance prevented the Professor from telepathically contacting his students directly, he was able to make contact with Jeffery Saunders, the mentally handicapped grandson of a deceased friend of his, whose mental state meant that he lacked the conflicting thoughts that had prevented the Professor reaching the X-Men. Using Jeffrey's physically superior body, the Professor was not only able to alert the X-Men to the deception- thanks to Iceman (The only member of the team to see how the Professor treated the real Jeffrey) realizing that the duplicate was acting out-of-character, but later defeated an ionic duplicate of Archangel that could have allowed Lucifer to use the portal to return to their dimension. With Xavier's return, the machine is destroyed, leaving Lucifer to fume and plot his revenge in the Nameless Dimension once again.