Diamanda

Diamanda, also known as Madame Tarot, was a spiritualist who pretended to speak to the dead. When Harry Houdini discovered she was a deciever, she trapped him and, later, the Twelfth Doctor and Clara Oswald inside a crystal ball. Although Houdini, the Doctor and Clara escaped, Diamanda was completely consumed by the crystal's computer program. (COMIC: Theatre of the Mind)