Spoilers for Marauders #5 ahead!
Professor Xavier's diabolically evil, genocidal sister Cassandra Nova recently bonded with the Venom-like mutant symbiote called Zzxz, wielding their sinister combined might to take down the villainous Nemesis and save her X-Men teammates from destruction in the pages of Marauders #5.
Cassandra Nova was first introduced as the major villain of Grant Morrison's beloved 2001 run of New X-Men, eventually revealed to be the psychic twin of Charles Xavier that he thought he killed in the womb, but who instead survived and grew to be a powerful and sociopathic psychic entity called a "mummandrai." While Nova has been "killed" or "cured" several times, Kate Pryde was forced to recruit her to join her new team of Marauders, working with other mutants like Bishop, Daken, and Psylocke to investigate reports of billions-year-old ancient mutants being kept imprisoned by the alien Shi'ar.
Marauders #5 - written by Steve Orlando (Spider-Man 2099: Exodus, Curse of the Man-Thing) with art by Andrea Broccardo (Deep Beyond, Star Wars: Doctor Aphra) and Matt Milla (X-Terminators, Crypt of Shadows) - is the conclusion to the team's Shi'ar Empire arc that has seen their captain Kate Pryde murdered and the Majestrix Xandra of the Shi'ar assassinated. Using Tempo's time manipulation abilities, the surviving team went back to Magneto's 1990s base Avalon to fight Nemesis and the Acolytes in an attempt to rescue an ancient mutant that was apparently trapped there. Much of their battle up to this point has been against the Shi'ar secret military group known as the Kin Crimson, and in Marauders #4 it was revealed the Kin Crimson's incredibly powerful "wet skin" was developed using the power of the Kylntar symbiote mutant called Zzxz. Zzxz is perhaps the only "mutant" symbiote in existence, surviving by eating their host's brains as opposed to draining their adrenaline in the style of regular symbiotes like Venom, and Cassandra Nova apparently made a deal with Zzxz that if she rescued the symbiote from the Kin Crimson, it would provide protection for her.
As the Marauders go back in time and enter Avalon, Nova is almost immediately drained of her life energy by the villain Nemesis, which prompts Zzxz to activate and bond with Nova, not only reviving her but fully giving her the powers and look of a terrifying Venom-like symbiote. Cassandra Nova is already a truly horrifying villain, and to see her fighting bonded with a ruthless creature like Zzxz is all the more scary, although Nova manages to not slaughter anyone and actually protects her Marauders teammates from their foes. In the Krakoan Age, Nova has rebranded herself as a mutant, and is now apparently feverishly dedicated to the preservation of mutantkind's future, so it makes sense that she would make a deal with a mutant symbiote and actually honor the deal - something she never would have done in the earlier days of her character history.
By the end of Marauders #5, Cassandra and Zzxz have thankfully been un-bonded, with Zzxz being allowed to bond with the Shi'ar warrior Warbird and Nova returning to Krakoa with the rest of the Marauders. Still, it was impressive that Nova fought so bravely for her people with the power of Zzxz, and even more impressive that the decidedly still villainous Cassandra kept her word and made sure Zzxz got a proper host.
After Charles Xavier's horrendous actions over the past several years as leader of Krakoa, there is a chance that one day Cassandra might actually be viewed as more of a savior to mutants than Charles, even though she almost annihilated the population years ago. Either way, Nova bonding with the Venom-like symbiote Zzxz to save the X-Men was a remarkable display of power and collaboration between two typically villainous characters!
Marauders #5 is available in stores now from Marvel Comics.