Acererak

The evil wizard Acererak is said to linger in his ancient tomb in undead form. Originally a powerful lich, he has become a demi-lich, a more powerful form of undead.
He was the son of a human woman and a demon. Despite his hideous deformities, his mother raised him until, at age of ten, some superstitious villagers burned down his house. Acererak survived, but his mother didn't. This episode, and events that followed, lead him on the dark path toward necromancy and revenge against humanity.
Acererak became a powerful wizard. As he grew older and saw the specter of death looming, he sought out and completed the ritual for becoming a lich. After he assumed his undead form, his power continued to grow for centuries more. Eventually, he felt the power animating his undead body begin to decay. Knowing that his existence was about to end, he decided to build himself a secret place, where he would lure victims, to steal their souls and prolong his existence.
After stealing some souls from Raborahn, he regained his physical body.

Abilities
Being undead, any negative energy (such as that of an inflict spell) makes him stronger instead of damaging him. Also, the gems in his skull can capture and trap inside them the souls of anyone who tries to challenge him

Anyone who falls under his influence, would acquire some abilities:
- Detect undead
- Hide from undead
- Lich's Immunities: immunity to cold and electricity damage
- Paralyzing Touch

Followers
Gordaner, a mortal who had been killed and devoured, has been brought back to existence as a spirit of vengeance UPDATE: Cecilia_Lockridge managed to steal his soul from the lich
Edward_Walker wanted immortality and power, and sold his soul for that
Satiene_Deadcaller, after being killed by Gordaner, joined him as undead
There are rumors that he has made a secret deal with the Orcish_Clan... with Shagun in particular
Shagun captured the soul of Warog, the ex leader of the clan, who now serves the lich.
Thanks to the unwilling help of Shagun and Gordaner, the lich took possession of his old kingdom, Scorchmore