Karavakos was a tiefling wizard who lived in Estorium. He eventually grew discontent with his lot in life, and summoned an army of devils to take over the empire. Though his initial conquests were successful, the full might of the imperial army was soon brought to bear upon him. His armies were destroyed, and he was imprisoned within the Pyramid of Shadows.
Karavakos was not content to remain in his prison, however, and began researching means to escape. Though he succeeded in opening small rifts to both the Far Realm and the Plane of Shadow, he never found a way to escape through them.
The centuries he spent in the Pyramid of Shadows ultimately led to him gaining a considerable degree of control over its energies, as well as driving him mad. During a battle with the Challengers of the Unspeakable, he channeled the pyramid's power directly into himself, dramatically increasing his power and rejuvenating him. The immense power ultimately proved beyond his ability to control, however, and the arcane power exploded violently out of his body, vaporizing him.