Cassandra Nova began life at the same time as Charles Xavier. Conceived without a body, Cassandra improvised one by copying Xavier's DNA to make her own body, effectively becoming his twin sister. She grew with her brother until the time when Charles sensed her monstrous thoughts. Charles attempted to kill the creature, resulting in its physical body being stillborn. Despite this, the creature survived as chaotic cellular matter and clung to a sewer wall for decades, rebuilding its physical form and perfecting its effort to mimic human traits. During this time, she grew convinced that the womb in which she had fought Charles and the universe she now inhabited were one and the same, a universe in which only she and Charles were real, and that her purpose was to destroy every illusion Charles held dear: his dream, his X-Men and his beloved Lilandra. Jean Grey later discovered that Cassandra Nova is the mummudrai (from a Shi'ar legend, meaning opposite) of Charles Xavier. "Legend says each of us faces our own personal mummudrai in the womb, shortly before birth - it is our first experience of the alien, the other, the different". In reality, the mummudrai are a parasitic species born bodiless on the astral plane, and it was only through becoming entangled with Charles Xavier's developing telepathic mind that Cassandra Nova created a body for herself.
After she was able to rebuild herself, Cassandra returned with a vengeance. She convinced the last living relative of Bolivar Trask, Donald Trask III, to activate a pair of enormous wild Sentinels and send them to destroy the mutant homeland of Genosha, killing 16 million mutants. Cassandra duplicated Trask's DNA so she could also issue orders to the Sentinels, programmed to obey only those with the DNA of a Trask. Cassandra infected her own body with millions of nanosentinels just as she was captured by Cyclops and Wolverine. Cassandra was taken to the X-Mansion, where she broke free and defeated most of the X-Men easily. Cassandra then put herself into Xavier's machine Cerebra (an enhanced version of Cerebro) and switched minds with her brother before Emma Frost snapped Cassandra's neck (Emma had been in Genosha teaching during the attack and witnessed her students massacred). Trapped in Cassandra's broken body, Xavier was unable to warn the X-Men before Cassandra, now in Xavier's body, shot him.
Now in Xavier's body, Cassandra mentally forced the Xavier Institute student Beak to beat Beast into a coma after he discovered that Xavier and Cassandra shared the same DNA. Cassandra Nova then contacted the Shi'ar, whose leader was Majestrix Lilandra, Xavier's lover. Cassandra manipulated the Shi'ar Imperium, driving Lilandra insane and using her to make the Shi'ar Imperial fleet destroy the empire. Cassandra also made Lilandra send the Shi'ar Imperial Guard to wipe out the mutant population of Earth, starting with the X-Men. The Guard fought the X-Men until they were able to show the truth to the Imperial Guard. Angered at Cassandra's treachery and realizing the danger she posed, the Imperial Guard fought Cassandra, who defeated them and headed into the mansion. She had planned on using Cerebra to eliminate all mutants. However, Jean Grey (who was becoming increasingly powerful due to a manifestation of the Phoenix entity) was able to split Xavier's consciousness into pieces and store a little part of him in every single living mutant mind. When Cassandra used Cerebra and focused on all the mutants, the pieces of Xavier's mind were brought back together; at the same time, Jean Grey telephatically attacked, successfully defeating Cassandra , and forcing her out of Xavier's body. Without a body, Cassandra became pure psychic energy, bodiless and blind. Emma Frost tricked Cassandra into returning to what appeared to be her old body, which was in reality the alien polymorph "Stuff." Cassandra's essence entered the body and was locked into a self-repeating program in the synthetic brain.
Cassandra, back in her original form, returned in the "Danger" story arc of Astonishing X-Men, alongside Sebastian Shaw of the Hellfire Club. During this arc it was implied that Frost's survival of the destruction of Genosha in New X-Men #115 was due to Cassandra Nova catalyzing Frost's secondary mutation. In exchange, Emma was to assist Nova as part of a scheme to infiltrate the X-Men as a sleeper agent (Nova having erased the memory of their encounter at the time). However, it has yet to be stated whether this was real or a false memory implanted by Nova. This infiltration occurred when Emma tricked Cassandra into entering what appeared to be her original body: Cassandra managed to plant a seed of her consciousness into Emma's brain. She then played up on Emma's survivor guilt over not perishing during the Genosha massacre and also her general guilt over her past life as the villianious White Queen in the Hellfire Club. Cassandra's influence resulted in Emma creating manifestations of Cassandra in her human form, Sebastian Shaw, Emma's younger self as the White Queen (calling herself "Perfection"), and Negasonic Teenage Warhead, a former student of Emma's who was killed in Genosha. Emma and these manifestations then proceeded to attack the X-Men; Beast was reduced to a feral animal, Wolverine regressed to his past James Howlett identity as a timid child, Kitty lost control of her phasing ability, and Cyclops lost the use of his powers and was rendered catatonic. Meanwhile, Emma/Cassandra subjected Kitty Pryde to a cruel dystopic vision that tricked her into using her phasing powers to open the containment chamber where Cassandra, trapped in Stuff's form, had been imprisoned. Afterwards, Kitty was to murder Frost and the rest of the X-Men, as Nova's permanent host. Cassandra's plans were foiled by a revived Cyclops, and other students at the Xavier Institute (including Blindfold and Armor). Cyclops revealed that while "Cassandra" had influenced Emma to recruit Kitty to free her from the container, Emma had actually recruited Kitty to the team to kill her in the hopes that this would thwart Cassandra's plans. Admitting that Kitty was too much of a challenge to possess, Cassandra then attempted to have Emma transfer her mind into Hisako. While Cassandra was attempting to manipulate Emma on the astral plane, Scott was talking to Emma in the physical world, trying to convince her to return Cassandra's mind to Stuff. Emma's only response was to say "Go to hell," though it is unclear whether she was talking to Scott or Cassandra. It is as yet unknown if Cassandra's possession of Hisako was successful, or if Emma returned her mind to its prison.
Powers and Abilities
Cassandra possesses telepathy comparable to Charles Xavier. After copying the DNA of Charles Xavier, the mummudrai Cassandra Nova accessed the full spectrum of latent mutant functions in his genome (this means she has the powers of Charles Xavier, the ones he could have had and the ones he might receive, as a result of latent mutation), granting itself vast psionic powers. These powers include: telepathy, telekinesis, and the ability to release an astral form, which she focuses both her telepathy and telekinesis. She has all the powers of the "average" mummudrai as well.
DNA Duplication: able to copy the DNA of sentient beings and use it to construct physical bodies for themselves. Also capable of accessing the full spectrum of latent mutant functions in ones genome.
- DNA Manipulation: can manipulate the DNA of others, breaking it down at the molecular level.
- Jumpstart: After analyzing the DNA of another superhuman mutant, Cassandra is able to selectively evolve their existing genetic traits as well as catalyze the untapped genetic potential of latent mutants. Once begun, the procedure is irreversible and can often result in unpredictable side effects.
- Phasing: ability to pass through solid matter by passing her atoms through the spaces between the atoms of the object through which she is moving. In this way she and the object through which she is passing can temporarily merge without interacting, and each is unharmed when Cassandra has finished passing through the object. This process is called “phasing.” When Cassandra is phasing she is intangible.
- Metahuman Regeneration: She regenerates and heals hundreds of times faster than a normal human. Thanks to this superhumanly regenerative "healing factor," she has been able to completely recover from injuries which would prove fatal to most humans, even those with superhuman abilities. She can regenerate organs such as eyes or large portions of flesh, regenerate limbs, such as feet and arms, which have been completely severed.
Astral Form Projection: ability to release her astral form, which she uses to focus her telepathy and telekinesis.
- Telepathy: can read minds and project her thoughts into other minds within a vast, potentially limitless radius.
- Telepathic Cloak: Can mask her presence from being detected by others. Her abilities can at times go undetected or be counteracted by other more powerful telepaths depending on their level of skill in using their own psi abilities. She can extend these defenses to others around her as well.
- Mind Control: ability to control the minds of others upon mere concentration.
- Mind Possession: ability to possess the mind of another, and use that beings body as your own
- Mind Alteration: ability to alter the minds of others by force of will.
- Psionic Shield: ability to erect a psychic shield for protection of himself and of others minds
- Telepathic Illusions: ability to create illusions to make herself seem to be invisible, look like someone else, or make others experience events that are not truly happening.
- Mental Paralysis: ability to induce temporary mental or physical paralysis
- Mental Amnesia: Can erase any awareness of particular memories or cause total amnesia.
- Psionic Blasts: can project psionic force bolts which have no physical effects but which can affect a victim's mind so as to cause the victim pain or unconsciousness and turning someone brain-dead.
- Astral Projection: can project her astral form from her body onto astral planes or the physical planes. In the physical plane she can only travel in astral form over short distances. In the astral plane, she can mentally create psionic objects and manipulate the aspects of her environment.
- Mind Transferal: able to transfer both her mind and powers into other host bodies should her own physical body be somehow killed
- Mental Detection: can sense the presence of another superhuman mutant within a small but as yet undefined radius of himself by perceiving the distinctive mental radiations emitted by such a being.
- Telekinesis: possesses telekinetic abilities enabling her to levitate and manipulate living beings, inanimate objects, and to some extent energy psionically. She can levitate herself or other persons or project a telekinetic shield capable of withstanding missile blasts. By focusing her mental energy at a specific target, she can release devastating force blasts