Sacred Lady Lenya, colloquially known as Mother Keizaal, the Lady of Mercy, and the Healing Mother is an unseen character in Game of Thrones. She lived and died centuries before the events of the series, and is not expected to appear. She was the first wife of Asterion the Black and helped him in his journey to the Borderlands.
Lenya's origin has been obscured into history. The only thing known about her heritage, is that she was born in the Stormlands. Lenya was infamous for being an experienced sorceress.
Lenya was one of Asterion's assassins and the main conspirator in his assassination.