Slavic bestiary: Eretik

The Russian vampire or Eretik became closely associated with the witch and the sorcerer and the concept of heresy. This view derived from the religious movements that pitted Orthodox Christianity and pre-Christian or pagan practices. A heretic, or a person who deviated from the church, would become a vampire after death, strengthening the connection between the two as interchangeable.
The Eretik, a sorcerer who would eventually turn vampire, were noted for having the “evil eye,” having sold their souls to the devils, and could often draw victims into their graves by merely catching their gaze. To destroy a Eretik, one would drive an aspen stake into their back or use fire.
In the Olonecian region of Russia, “accounts suggested that any person, including a pious Christian, could become a vampire if a sorcerer entered and took over the body at the moment of death”.