Source: The Final Wish, pg(s). 44-45
Jhavhul is an efreeti prince who traveled to the Material Plane in order to impress his cruel mistress, Ymeri, Elemental Queen of the Inferno. He was captured by a wizard-priest named Ezer Hazzebaim, who used him in his search for the corpse of Xotani the Firebleeder, one of the monstrous Spawn of Rovagug. Jhavhul managed to extricate himself from the control of the wizard-priest, and Ezer escaped to the Plane of Fire. Jhavhul continued to search of his former master, hoping to take on Xotani's traits and impress Ymeri. Jhavhul located the Firebleeder's immense remains beneath the Brazen Peaks. To accomplish the transformation he needed 1,000 wishes from the mouths of mortals, and so became a ruler of a temple devoted to Rovagug, a place that now is known as the House of the Beast. Jhavhul's wishes fractured reality to such an extent that they attracted the attention of the djinni princess Nefeshti. She sent her forces, led by the Templars of the Five Winds, to trap Jhavhul and his minions in a forgotten demiplane in 4300 AR.