BIOGRAPHY page 1
Martin Preston was Hollywood royalty, a leading man and actor for twenty-seven years. Preston loved life and all it brought him to excess, which led him to driving his convertible at top speed down the Pacific Coast Highway with a bottle of alcohol as his co-pilot. Fatefully, inevitably, he took the corner too sharply and plunged over the edge of the cliffside.
Preston recovered from the shock to find himself hanging upside-down, his car caught in a series of tree branches, but he himself was still safely held inside the car by his seat belt, barely scraped. His cheer turned to horror, however, when he turned his head and saw one entire arm had been torn off in the accident.
Screaming to heavens above and hell below about his loss, Martin Preston surprisingly received an answer in the form of Mephisto. The Lord of Lies queried if Preston was really willing to 
exchange his soul for the return of his arm and health, and Martin agreed. Mephisto naturally put his own sinister twist on their agreement. Instead of restoring Preston's own arm, he summoned a demon, ripped off one of its arms, and attached it to Martin's body. To complete the set, Mephisto whimsically decided to rip off Preston's other arm and replace it with a demon's limb as well.
When he awakened in his bedroom the next morning, with no disfigurement or injuries, Martin briefly thought it had all been a dream. His arms then moved of their own accord, opening his shirt to reveal a hole in his gut the shape of an inverted pentagram, a five-pointed star. Mephisto 
appeared to Preston and explained his cruel jest. The idea of souls for favors had lost interest to him some time ago, and so Mephisto thought instead to be creative with this deal. He offered Martin the chance to get his soul back, but it had been splintered into five shards, hidden away with five different demons in five different parts of reality. The quest to regain his soul would require Martin Preston to become a villain of legendary pedigree and cause all manner of havoc and disorder in his wake... all for Mephisto's amusement. [West Coast Avengers (2nd series) #9,15]
Preston acted just as Mephisto had intended, developing a monomaniacal obsession with finding the demons he came to know as "The Five." As an abode for demons, Preston now had many supernatural powers to support his quest, such as levitation, breathing fire, and superhuman strength from his demon limbs. Naturally, he could also expel his demons as familiar to act on his behalf as well. Preston owned Anvil Studios and continued to make use of the business as a front for his new quest, although it was largely abandoned as an active production studio. [Avengers West Coast #50, West Coast Avengers (2nd series) #9] He crafted an identity as the masked Master Pandemonium and began immersing himself in the world of the occult. Pandemonium bolstered his efforts by acquiring the Amulet of Asmodeus, a potential threat to his mission, and turned the demon inside into an agent acting on his behalf.
One day, Asmodeus directed Master Pandemonium to a heroine named Firebird, suggesting she had the aura of demonitry around her. Firebird sought assistance from the West Coast Avengers, 
bringing Pandemonium to the attention of the California-based heroes. The villain and his Rakasha demon hordes battled the Avengers to a standstill before he and Asmodeus fled. Master Pandemonium had made new enemies, yet was no closer to finding any evidence of The Five. [West Coast Avengers (2nd series) #4]
In his next encounter with the Avengers, Master Pandemonium was summoned by a demon posing as Shooting Star, one of Firebird's former teammates from the Rangers. Pandemonium thought perhaps the demon aura detected around Firebird came from this demon, and intervened to protect "Star" from the West Coast Avengers so he could determine if she were one of The Five. In fact, the Avengers had set up a sting operation for Master Pandemonium, with Mockingbird posing as Shooting Star. They pursued Pandemonium to Anvil Studios, where Mockingbird learned some of Preston's origins. Master Pandemonium received an unexpected threat from another Avenger, Tigra, whose patrons the Cat People wanted him dead for their own reasons. Still, Pandemonium was able to escape from Tigra and the Avengers before they could capture or kill him. [West Coast Avengers (2nd series) #9]
Hank Pym investigated what Mockingbird had learned about Master Pandemonium's origins in an effort to track him down for the Avengers. This drew the attention of the demon Allatou which, ironically, also drew out Master Pandemonium. Allatou confronted the West Coast Avengers for imposing on her territory, and her gathering of demon hordes caused Pandemonium to arrive as 
well in search of The Five. Several Avengers were captured by Allatou, who fled, leading the other Avengers to seek the help of occult investigators Hellcat and Hellstorm to find them. Another three-way battle occurred in Allatou's realm as Master Pandemonium tracked the Avengers to Allatou. The conflict ended when Allatou cast Pandemonium and the Avengers adrift on a boat following the River of Death, which ran through her realm. [West Coast Avengers (2nd series) #14]
With no immediate reason to fight, Master Pandemonium and the Avengers had a detente as the river carried them they knew not where. Eventually, they passed through a nether-realm portal that brought their boat to the Land Within, realm of the Cat People. Tigra learned for the first time that the Cat People were, in fact, demons... and that they possessed one shard of Pandemonium's soul, which is why they feared him. Preston was dismembered so that Tigra could fulfill her vow to them and kill him, but she 
ultimately remained true to her oath as an Avenger and refused to murder the villain. In the breakout that followed, the Avengers distracted the Cat People long enough for Pandemonium to reclaim his limbs and seize the soul jar that contained the fragment of his soul. He merged with the soul, removing one point from the inverted pentagram hole in his gut. Gleeful over having finally made some headway in his quest, Master Pandemonium cheerfully departed from the Avengers and the Cat People, swimming upriver in the Land Within to continue his efforts. [West Coast Avengers (2nd series) #15]
Master Pandemonium soon came to another of the inter-dimensional warps that connected the nether-realm, and found himself light-years away on the planet Arcturus IV. Unable to return to Earth under his own power, Pandemonium was trapped on that distant world for months until the Fantastic Four inadvertently followed the same path through the warp after departing the Land Within. After a brief skirmish, Pandemonium convinced the FF that he had no grudge against them, and only wanted to return home. The arrival of Comet Man and the Fortisquian Max led to the discovery of the necessary warp home, and Master Pandemonium quickly abandoned his traveling companions before they thought to restrain him. [Fantastic Four (1st series) #314-316]
The rush from his victory in the Land Within eventually faded, for Master Pandemonium found no new leads in his search for the remaining Five. Eventually, Preston conceived a new plan to feed off of other souls in replacement for his own lost soul. He made the curiously astute choice to kidnap Thomas and William, infant sons of Vision and the Scarlet Witch, in order to use their nascent beings to replace two of his soul shards. (This decision was apparently influenced by Immortus, for his own reasons.) [Avengers West Coast #62]
Master Pandemonium assaulted Avengers Compound with the Raksha, distracting the Avengers as he made his way to the family bungalows. After stealing the children away, Preston magically 
bonded with them, having the boys attached in place of his traditional demon limbs like Satanic puppets. Somewhat miraculously, Master Pandemonium discovered the twin boys actually WERE two of his missing soul fragments. When the Scarlet Witch used an enormous amount of magic to bend probability and cause herself to conceive children with her synthetic husband the Vision, her spell had apparently seized two of Pandemonium's shards from the ether as nexii for cultivating the new life in her womb.
Master Pandemonium was flush with tremendous power achieved through the bonding. When the Avengers arrived in the realm of the Raksha he commanded, Pandemonium easily overwhelmed his foes. He next planned to add the soul of the twins' mother Wanda to his essence in the hopes of further power. However, Wanda's witchcraft tutor Agatha Harkness dispatched the Human Torch with an even grander prize -- the last two remaining fragments of Pandemonium's soul. Preston greedily agreed to anything the Torch asked in order to get his hands on the soul shards, 
and then placed them in the two remaining slots in the pentagram on his gut. Instead of completing his missing soul, however, Pandemonium discovered the center of the pentagram remained unfilled. Master Pandemonium only had seconds to contemplate this anomaly before he was swallowed up into the demon abode in his own chest, turning the sorcerer inside out as Mephisto emerged from the void.
Mephisto explained that Martin Preston had never been hunting for his own soul, despite the Lord of Lies' claims to the contrary. Not long before Preston's car accident, Mephisto was horribly injured by the vast psionic powers possessed by Franklin Richards. His essence was scattered throughout the dimensional planes and, while he was able to reform himself, five fragments of Mephisto's power remained at large and out of his control. Instead of bothering to seek out and reclaim his fragments himself, Mephisto empowered Master Pandemonium and manipulated the man into doing the work for him. All of this was explained to the Avengers for, after Mephisto's arrival, no more was seen of Master Pandemonium at all. [Avengers West Coast #51-52]
[Note: In AWC #52, several parties repeatedly claimed that Thomas and William were born before Master Pandemonium made his deal with Mephisto. This is false. The twins were only just conceived in December of 1985, and Master Pandemonium debuted one month later, having already been searching for his soul shards for some time.]