She is portrayed by Helen McCroy.
Evelyn debuts when she is shown taking a bath in the blood of a recently killed young girl. After the other witches appear, having failed in a mission to capture Vanessa Ives Evelyn had ordered of them, Evelyn murders one of them as a warning to the others, then sends Hecate off to murder a family, including a young baby, as her magic requires the hearts of children. Hecate succeeds in the mission.
It is later revealed that Evelyn had engineered the death of her sister, Joan, who she had been rivals with. Evelyn had used her powers to cause harm to the village, blaming Joan for the crimes, leading her to be killed by the superstitious villagers.
Evelyn would proceed to torment Sir Malcolm Murray and his wife, ultimately culminating in forcing Malcolm's wife to commit suicide. She used hallucinations to convince Malcolm that his dead children had risen from the dead. She also trapped the lycanthrope Ethan Chandler in her tower, along with his best friend, Sembene.
Evelyne's reign of terror came to an end when Vanessa managed to break Eveyn's immortality, after which she was betrayed by Hecate and murdered by Ethan.