Despite being the main villain of four different X-Men storylines, Cassandra Nova has left quite the trail of devastation in each of her appearances. Cassandra Nova, in her quest for vengeance against her twin brother, Professor X, committed various atrocities against Mutantkind. Her only goal is to ruin Professor X's dream of mutant and human cohabitation as retribution for him almost killing her in the womb.
While Cassandra Nova has done many horrible things, some are worst than others. This article will examine the ten worst things that Cassandra Nova has done and ranked them by how devastating their impact was.
10 Outing Professor X As Mutant To The World
The conclusion of the "E for Extinction" storyline saw Professor Xavier reveal to the world that he was secretly a mutant. It was later revealed that Professor X's body at the time was being possessed by Cassandra Nova as a part of her plan to ruin his life.
While the damage caused by her outing of Professor X as a mutant was later turned into something that benefits the X-Men's cause, it initially painted a target on the back on everyone associated with Professor X. This can be seen in the next story arc when the X-Men had to deal with an anti-mutant attack on Xavier's School.
9 Pinning The Blame On The X-Men For A Death She Caused
Cassandra Nova's most recent appearance was as the main villain of the X-Men: Red series. She first appeared in the series when she possessed a UN representative and made some cryptic threats towards Jean Grey. When Jean Grey tries to probe the representative's mind, Cassandra Nova blew up the representative's head.
Cassandra Nova timed the explosion to make it look like Jean Grey killed the representative. This pinned murder led to Jean Grey and her team of X-Men being labeled as terrorists by the international community. It also temporarily damaged Human-Mutant relationships until the X-Men were able to prove their innocence.
8 Mind Controlling Beak Into Beating Beast Into A Coma
Shortly after Cassandra Nova began possessing Xaiver at the end of "E is for Extinction," Beast finds out about it. To prevent him from revealing the truth to the rest of the X-Men, Cassandra mind controls Beak, a young mutant visiting Beast's office, into brutally beating him with a baseball bat.
This attack left Beast in a coma and the X-Men imprisoned Beak, initially thinking that he attacked Beast on his own free will. The attack on Beast buys a Cassandra Nova possessed Professor X time to leave for the Shi'air empire, where she would cause even more destruction.
7 Tricking Donald Trask III Into Reactivating A Master Mold
One of Cassandra Nova's first heinous acts was tricking Donald Trask III, the nephew of Bolivar Trask, into reactivating a Master Mold in the Ecuadorian jungle. This trickery occurred through Cassandra posing as a government agent and telling Donald that the government needed his dentistry skills. In reality, she wants Donald Trask III's DNA to reactive the Master Mold.
After getting Donald Trask III to reactivate the Master Mold, she then painfully extracted his DNA for later uses over eight hours before killing him. Cassandra would then use the Master Mold to produce Sentinels for future atrocities.
6 Deluding Emma Frost Into Betraying The X-Men
Cassandra Nova's first appearance after Grant Morrison's run on New X-Men was during the "Torn" storyline of Astonishing X-Men. In this storyline, it was revealed that during Cassandra's previous defeat, she placed a psychic suggestion in Emma Frost's head that deluded her into thinking that she only joined the X-Men to free Cassandra.
Emma Frost's delusion led to the "Torn" storyline, where she betrayed the X-Men by mentally torturing them to either defeat them or make them aid her effort to free Cassandra. In the end, Cassandra's plan succeeded in freeing herself but failed to find a new host.
5 Stoking Mutant Hate Crimes
Before revealing her return to Jean Grey's X-Men, Cassandra Nova was secretly using her psychic power to stoke anti-Mutant hate crimes. The rise of anti-mutant hate crimes would lead Jean Grey to form a new X-Men team to deal with the recent rise of Mutant hate crimes.
These hate crimes, psychically stoked by Cassandra Nova, are particularly heinous in that target mutants regardless of age. This is seen in the opening of X-Men Red #1 when a young Mutant child is attacked by an angry mob that includes her mother.
4 Causing The Shi'ar Empire To Attack Xavier's School for Gifted Youngsters
The "Imperial" storyline of New X-Men sees a possessed Professor Xavier tricking the Shi'ar Empire into believing that the Earth's entire mutant population was infected with a psi-plague. This psi-plague freaked the Shi'ar Empire out enough to send their best Imperial Guardsmen to Earth to sterilize it of all mutants.
This sterilization effort led to Xavier's School for Gifted Youngsters to be under siege by a bunch of super-powered aliens, threatening the lives of a bunch of young Mutants at the school. The attack also provided a distraction for Cassandra Nova to fulfill her actual plan.
3 Attempting To Use Cerebra To Murder Every Mutant In The World
Cassandra Nova's actual plan in the "Imperial" storyline was to gain access to the X-Men's computer, Cerebra. She planned to used Cerebra's ability to boost a telepath's power to take revenge against Xavier. That revenge would be conducted by using her boosted telepathic ability to cause every Mutant in the world to kill one another.
Cassandra's plan only failed thanks to the effort of Jean Gray and Emma Frost, who put Professor X's mind back in his body and forced Cassandra Nova back into a duplicate of her body. To prevent her mind from causing further problems for the X-Men, her body was encased by an alien.
2 Trying To Destroy The Shi'ar Empire
Cassandra's plan to trick the Shi'ar empire into destroying the X-Men failed due to her decision to possesses the crews of several Shi'ar spaceships. She used these ships to launch several attacks on worlds within the Shi'ar Empire. These attacks by the Shi'ar's own ships devastated worlds and killed millions of Shi'ar citizens.
These attacks made Empress Lilandra realized that something was manipulating the Shi'ar Military and demanded the Imperial Guard stop attacking the X-Men. While this realization prevents the destruction of the Mutant population, Cassandra's actions still caused a great deal of devastation to the Shi'ar empire.
1 Destroying Genosha
Cassandra Nova's most heinous action would be her role in destroying the island nation of Genosha. This occurred when she unleashed a bunch of Sentinels upon the unsuspecting populace of Genosha. This attack ended up wiping out sixteen million Mutants and an unknown number of humans.
The destruction of Genosha would lead to future atrocities. Xorn used this attack as justification for his violent take over of New York City. The number of dead Mutants was also used by the real Magneto as the reason for why he was aiding Professor X's mission to bring back every dead mutant in House of X.