Vecna

Vecna may truly be a unique being. Born as a mortal, risen as an undead lich, and transformed into a deity – Vecna proved the power of knowledge as well as his own pure strength of will.

Born as a mortal of an unknown race on an unknown planet, Vecna became the high priest of the local church of Morana. That did not save him from his fear of death; in fact, Morana’s void only frightened him more the longer she prolonged his life.
Driven by his fear, Vecna set out to find a way to deceive his goddess. Vecna abandoned his service and began creating a massive kingdom. To deceive the oldest goddess required many resources, and for that purpose, he began forming his army. All his subjects were turned into an army of undead, while many others were transformed into demons in his service.
Morana did not tolerate such an insult to her pantheon and her worship and decided to personally end Vecna. What she did not know was that Vecna had planned to die.
The ritual of becoming a lich is a secret and differs for each one. What is always the same is death. The wizard must die in order to become immortal.
Vecna further demonstrated that the glory and grandeur of death directly affect the power of the lich. Death at the hands of the oldest goddess gave Vecna perhaps the most glorious death of all.
Vecna rose from death as the most powerful lich in history. His power was already approaching the divine, and with enough time he found a way to become a true god through his own might. What stopped Morana from destroying him when he returned as a lich or after he became a god remains unknown.

Vecna is usually depicted as a humanoid lich missing his left hand and eye. Sometimes he is shown with withered, mummified flesh; other times he is shown as a creature of bare bone, without any remaining trace of skin. In some old sketches he is depicted as partially transparent, like a ghost. Regardless of what form of undead he takes, he is always shown with noble and rich details, alluding to his royal past.

The cult of Vecna operated in secrecy for most of the lich’s existence and was further emboldened after his ascension to godhood. They are a wholly evil group that recruits new members through blackmail and coercion. Like their god, these malicious priests seek to uncover lost secrets through dreams and divination and use them to accumulate power and gain control over others.

There are rumors that Vecna’s kingdom was based precisely in Solitude and that Morana leveled that city while killing him. As entertaining as such a story may be, there is no evidence of it.