Source: Secrets of the Sphinx, pg(s). 60
Userib is a muscular, powerful-looking, graceful maftet. His fur and wings, formerly golden, turned black after he converted to the worship of Areshkagal. The tattoos on his face have subtly twisted to give him a malevolent-looking face. To honour his new patron, Userib wields twin sickles and wears a striped crimson nemes headdress.
Userib was gifted with strength, grace, and wisdom from birth, and quickly developed the powers of an adept from a young age. His influence grew within the tribe, swaying even Pride Leader Erayu himself, who felt uncommonly proud of Userib, as if his leadership had somehow produced such a fine individual. Userib was spoilt and held to a lesser standard of responsibility than others, which exacerbated his growing selfishness and arrogance. He started to see himself as Erayu's successor, grumbling when reminded that the laws of succession were long set in place and could not be changed.
As Userib grew, Erayu started to notice that Userib did not see him as leader, but as an old man who should give up his power, and they often clashed in battles of word and will. When Userib led a group of scouts into the desert without Erayu's permission, they returned with fresh supplies, but one of them was injured by a desert giant, and had to undergo amputation of a leg to survive. Erayu blamed Userib alone, finally deciding that his influence must be curbed before he led the tribe to ruin.
Out of curiosity and rebellion, Userib led his friends into the taboo Sightless Sphinx, convinced that when he returned with loot and secrets, the tribe would let him take Erayu's place. Inside the Sightless Sphinx, he encountered the glabrezu Ninureset, whose Abyssal energies amplified and further corrupted the already-evil Userib, converting him from an adept to a cleric in service to the demon lord Areshkagal.