How is Morgause described in the novel, The Wicked Day?

Queen Morgause, the wife of King Lot, is described as a scheming woman who uses her dark powers to create poisonous potions, manipulate people, and cause distress and pain to others. She is vain and selfish, and her beauty is skin deep and kept together with her famous lotions and spells. She does have the skill of some visions, but is hampered from ever being as great as Merlin because of her evil nature. She is completely amoral: she seduces her half-brother, she is unfaithful to her husband, and when she is reunited with her son Mordred, attempts to seduce him as well.