Introduced as Billie Jenkins's long-lost sister, she secretly collaborates with the demonic council known as the Triad with their plans to destroy the Charmed Ones. She eventually convinces Billie that the Charmed Ones are corrupt, and use their power to fulfill their own personal desires, rather than help for the greater good. Billie kills Christy in self-defense after being unable to convince her to understand the Halliwell sisters were good, and to return home with her. Throughout season eight, Christy is shown to be a powerful witch with a mastery of her powers of telepathy and pyrokinesis. She is also called the Key to the Ultimate Power due to her connection with Billie, who is prophesied to be the Ultimate Power. Christy is referenced in canonical "Charmed" material such as comic books and novels.