He was a power hungry necromancer in a past life. His quest for power eventually drew the disdain of many guardsmen, who sought to destroy him before he could use his magic against the world. When they came to put and end to it, they quickly found that they were no match and he slew them to demonstrate his power to anybody who would seek to try to take him on again.
He continued his work trying to find the ancient secrets held by the ever living white liches that aged without decay. In his earnest to become unstoppable and grow his magical prowess, he accidentally caught his wife and daughter in a spell that went out of control. They were immediately obliterated and, even with all his power to bring people back from the dead, there was nothing he could for them.
He was overtaken with grief and decided to take his own life. As he lay dying, he realized this wasn’t what he wanted and prayed hard to be given a second to reverse the deeds of his past. He died none the less, his soul falling into the eternal blight of the nine hells where he was to burn for the rest of eternity. The fires that consumed him were nowhere near as torturous as the memories of how he had wasted his life in the world. Corellian saw his plight in the realm of Asmodius and decided to intervene.
She didn’t think that allowing him to retain his memories of the past would do any good as it seemed to be eating at him to the point where he was catatonic so she removed any sense of who he was and told him the only way he would be able to return to his family would be to use his evil powers for good instead. He had to recall how to use them and in his process he started to recall memories of his family but it wasn’t long before he met his end at the hands of a group of goblins that were trying to fulfill a prophecy about raising a goblin prophet to herald in the would be god Mat’ Suhn. He had failed to do enough significant good in the world and his soul was returned to the nine hells.
He again burned in the fires being held down by the beast his powers had sought to control on the material plane. Eventually the group he had been adventuring with broke into the realm to do battle with Mat’ Suhn. The party released him and he helped bind Mat’ Suhn in dragon form so that it couldn’t fly from them. When the battle was over, a bright light pierced into the darkness of the realm and his wife and daughter reached out from it beckoning him to join them. As they embraced him, the scars from his burns melted away and, with one last farewell, he flew off relieved of his strife.