Khay'tall was a Nubian slave in the Roman garrison of Jerusalem. It is said that he watched from afar as Jesus Christ was crucified and asked himself what kind of God would demand such a sacrifice from his children. His duties as a slave included to attend on the feasts and orgies of the commander of the garrison, where he noticed that some of the attendees were apparently more than human. At one night, he stepped to one of these beings, an Egyptian named Nehsi, and asked to be made like them.
After being questioned of his motives, Khay'tall answered that he knew that everyone was enslaved to something and that he wanted to be the slave of something of his own choosing. Impressed, Nehsi took Khay'tall as his ghoul for a century, before Khay'tall was released and sent to the occupied city of Carthage. In Carthage, Khay'tall met the christianized Toreador methuselah Michael, who sought to construct Heaven on Earth – the Dream. Khay'tall and Michael had several long discussions about the necessity of vice and temptation. Khay'tall heard the passion in the Toreador's voice and realized that the methuselah was already enslaved by his own dreams.
During the 5th century, Khay'tall began to regularly corresponded with Michael. He told that everything that was worth building had to be tested against corruption, otherwise, it would become dependent and enslaved. Khay'tall came to test Constantinople's perfection and pit himself against the Toreador at Michael's invitation, who even granted the newly founded "Children of Judas" his protection as a scion family. During his work, Khay'tall began to further distance himself from Setite authority, mainly against Nakhthorheb. He proposed that iniquity and corruption were the only true way in themselves, not merely tools for the servants of Set to use. His numerous childer did their best to undermine the Dream and during the end phase of the Long Night it became clear that Khay'tall had won his wager with Michael.
During the sacking of the city in 1204, Khay'tall was ambushed by his favorite childe, Sarrasine, who drained his corporeal form of all its vitae in an attempt of diablerie. Predicting this move, Khay'tall had his own heart previously removed via Serpentis and placed in a scarab amulet created by Gregorius Lakeritos. The amulet eventually came into the possession of the Setite Andreas Aegyptus, who delivered the amulet to the Red Temple of Thebes. His teachings, however, proved to be a far greater problem, luring unsuspecting neonates and ancillae into forsaking the authority of their elders and pledging themselves solely to corruption for the sake of personal pleasure.