Sorceress Cassandra

Cassandra is a devious she-wolf who wants vengeance on her sister, Ursa, for taking the title of queen away from her. She attempts to assassinate her sister and is banished from the kingdom. With a lust for power, she makes a deal with the king of the underworld, Darkness. He grants her the abilities of a goddess, the traits of a queen, and the soul of a demon. In exchange, she becomes his wife. She becomes ruler of the underworld alongside her husband and continues to strive for her sister's undoing. Cassandra vowed to never rest until she takes over the celestial kingdom and receives her 'rightful place' as the queen.