Cassandra Nova

Cassandra Nova Xavier is a supervillain appearing in American comic books published by Marvel Comics, most commonly in association with the X-Men. Created by writer Grant Morrison and artist Frank Quitely, the character first appeared in New X-Men #114 (July 2001). She is a mummudrai, a parasitic life form born bodiless on the astral plane. Cassandra is the twin sister of X-Men founder, the telepath Professor X (Charles Xavier). While in the womb together, Xavier recognized her evil presence and killed her, resulting in her stillbirth. The mummudrai that became Cassandra became telepathically entangled with Xavier, granting Cassandra some psionic powers herself, including the ability to exit the womb and create a body, with which she sought revenge on Xavier. As Xavier's ideological dark shadow who is bent on destruction and genocide, Nova is most infamous for being responsible for the massacre of 16 million mutants within the mutant homeland Genosha. In 2009, Cassandra Nova was ranked as IGN's 50th Greatest Comic Book Villain of All Time, the only villain introduced in the 21st century to make the list. The character made her live-action debut in the Marvel Cinematic Universe (MCU) film Deadpool & Wolverine (2024), portrayed by Emma Corrin.