Void Ascendant

The Void Ascendant is a Spellbound Ritualist who turn into void revenant located in Ny'alotha, the Waking City.

Speculation
Void Ascendands might be closely related to, or even the same as the Shadow ascendants from the RPG, Hearthstone, and briefly alluded to in the Cuffs of the Shadow Ascendant. Shadow ascendants are described as members of the Cult of the Forgotten Shadow, whereas Void ascendants are members of the Cult of the Void. While these cults are not one and the same, the rituals and transformations might be.