From Robert Jordan's The Wheel of Time series of books.
During the Age of Legends, Kamarile Maradim Nindar was a noted psychiatrist and ascetic, and when she turned to the Shadow she completly changed, becoming as hedonistic as she was reserved before.
Currently her exact whereabouts are unknown, but she has taken over a palace in Arad Doman and is posing as an old lady called Lady Basene. She has one of the great generals, Rodel Ituralde, working for her, and has been working with Sammael several times.