See his plays, ed. by R. H. Ball (1940, repr. 1965); biography by W. Winter (2 vol., 3d ed. 1925, repr. 1972).
To this end, he kidnapped Bice "Beatrice" dei Portinari, beloved of Dante, to give birth to the first of this new race. He fled with her to the Atlantean isle of Pangea, where the Elder Gods directed him to Mt. Flavius, where their summoning ritual could take place. While en route, Belasco raped Beatrice, and she was nine months pregnant by the time they arrived. He embarked onto the island, closely pursued by Dante, and took Beatrice into a network of underground passages designed to resemble Hell. Dante found them just in time to witness Beatrice dying in childbirth and, enraged, he attacked Belasco. During the battle, a pipe was accidentally struck, releasing an unknown liquid that placed Belasco in suspended animation. At some point on the island, Belasco also lost the locket containing the Bloodstones.
In recent years, the volcano mountain became active again, releasing Belasco. He quickly located the locket and found a new sacrifice, Shanna O'Hara. He placed her under his mental control and began the spell. He sought to make Shanna the mother of a demonic race he would father. However, just as he was almost finished, Shanna's mate Ka-Zar appeared and hurled the locket into the volcano, sealing away the Elder Gods and apparently destroying Belasco.
However, he instead was trapped in Limbo, also called Otherplace, where he spent his years conquering it. Once complete, he drew the X-Men to him for unknown reasons and battled them. They all managed to escape save the seven-year-old Illyana Rasputin. He made Illyana his apprentice, transforming her into a "demon sorceress." He shaped part of her soul into a Bloodstone, giving her great potential for power and allowing him to control her. However, upon reaching the age of fourteen, she rebelled against him, driving him from Limbo. Now its new master, she returned to her own world only seconds after the X-Men had returned, and shortly after joined the New Mutants as Magik. Magik was later deposed as the ruler of Limbo by the demons S'ym and N'astirh, the latter of whom was destroyed in the "Inferno" crossover, which also restored Illyana's lost childhood.
Belasco then attempted to transform Ka-Zar and Shanna into demons to be parents to a new demonic race. He was defeated when Ka-Zar impaled Belasco on his own sword. Belasco was next revealed to be the new master of the Cat People.
Belasco eventually took control of Limbo once more. The cultist Sammy Smith, alias "the Rev", who was a Jim Jones analogue, worshipped Belasco as Lucifer. Belasco sought to wipe out humanity, using Smith as a pawn. The Rev fought the Punisher twice, the second time alongside the Punisher's longtime foe Jigsaw. When the Punisher killed Jigsaw, the Rev used his Belasco-granted powers to resurrect the thug, although both were defeated despite Smith's gift of demonic magic.
Belasco also turned Alpha Flight-ally Witchfire against her team by influencing her demonic side. She finally was restored to normal and returned to Beta Flight, Alpha Flight's support group. It was strongly suggested during this story that Belasco is Witchfire's father or at least that Witchfire believes so.
Later, Belasco and the fear-demon D'Spayre contested to corrupt Cable, the son of Madelyne Pryor, who had been the ally of S'ym and N'astirh during "Inferno". Belasco banished D'Spayre and summoned himself, Cable, and Cable's ally Lee Forrester to Limbo, where S'ym threw Belasco out of his way and fought with Cable. Cable won, and he and Lee returned to Earth.
It was eventually revealed that Illyana's best friend Kitty Pryde had received Illyana's Soulsword after Illyana had died; in dying, she had bonded the Soulsword to Kitty's own essence. After Kitty's team Excalibur fought off several claimants to the sword, Nightcrawler's girlfriend Amanda Sefton was given the sword. She then gave the sword to her mother, Margali Szardos, who was in turn kidnapped by Belasco and brought to Limbo. Nightcrawler and Sefton freed her, and Sefton secretly took the sword and adopted the codename Magik for herself. Belasco and his allies, the N'Garai demons, fought the X-Men again soon after, but were defeated by the X-Men with the assistance of the new Magik.
Belasco is one of the most powerful sorcerers on Earth and possesses a wide knowledge of the mystical black arts. He possesses the ability to manipulate the forces of magic for a variety of effects, including the ability to fire concussive bolts of mystical energy, create protective shields of mystical energy, transform and transmute matter both living and inanimate, interdimensional travel, shoot mystical rays, control the minds of humans and animals, and the ability to raise dead under certain circumstances. He has an encyclopedic knowledge of spells from a variety of books of occult spells that he can use.
He was also endowed by the Elder Gods with immortality and apparent invulnerability. The exception to this is his own sword, which was forged by the Elder Gods themselves. It was this which cut off his right arm under unrevealed circumstances.
Belasco's powers are somehow linked to those of Magik. When they fought a battle in Otherplace and Magik took on her "Darkchilde" form, Belasco simultaneously reverted to human form, losing most of his power and his invulnerability in the process.
He has also come to possess a wide knowledge of the advanced technology left by the Atlanteans in Pangea.
Additionally, he is an exceptional swordsman and battle tactician and was seen wielding a battle axe with great skill.
As the demon lord, Belasco has red skin, a prehensile tail, pronounced fangs, glowing red eyes with no visible iris, small horns on his forehead, pointed ears, and as a result of an early conflict, only one arm.
During the "Black Sun" conflict, he had a restored arm and his horns were more pronounced. He has since lost the arm and the longer horns.