Played by series regular Jessica Lange, Fiona is about as close as the show gets to royalty. She's the Supreme, a once-in-a-generation witch with extraordinary magic — think the Slayer, but for witches. Even after being cursed with incurable cancer to make way for a new Supreme, she won't go down without a fight, entangling herself with voodoo in a quest for immortality. Ultimately, nothing she does is enough, and she dies of her disease in her daughter's arms.