SPOILER WARNING: The following article contains major spoilers for X-Men Red #11 by Tom Taylor, Roge Antonio, Rain Beredo and Cory Petit, on sale now.
Jean Grey’s team of X-Men in the pages of X-Men Red might not have had the longest run of any X-Men team in comics, but they’ve certainly made their mark in the year that they were here. Over the course of eleven issues, Tom Taylor and his collaborators have introduced a brand new mutant in Trinary, reinvigorated one of the most overlooked mutants in Gentle, and proven why Jean Grey is the right person to the lead the X-Men as we head into a new decade.
Jean’s team have been waging a war with the dark mirror of Charles Xavier known as Cassandra Nova, who has been using nanomachine Sentinels to spread her campaign of hate against the mutant race. But heading into this final issue, Jean has not just rallied the X-Men but the entire superhuman community of the Marvel Universe to take the fight to Professor X's evil twin sister. The question remains: how do you stop a being made entirely of hate? The answer is, of course, with the most powerful force not just in the Marvel Universe, but in our own universe.
To understand Cassandra Nova, you need to fully understand not just who she is but what she is. The quick and easy explanation is that she’s Charles Xavier’s twin sister; the complicated explanation takes a little longer. Cassandra Nova isn’t human and she’s not even a mutant, she’s a mummudrai.
According to the alien race known as the Shi’Ar, all living beings are conceived with a shadow-self which they must defeat in the womb in order to be born. Charles Xavier’s mummudrai copied his DNA and in doing so gained his powers. And while most mummudrai are defeated, the being that would become Cassandra Nova was able to survive, and spent decades constituting a body for itself in order to get revenge on Xavier.
Of course, the best way to hurt Charles Xavier is to target his dream of a peaceful world for mutants and humans, and to that end she set about razing Genosha to the ground. With the power of the Wild Sentinels, Cassandra Nova murdered sixteen billion mutants in a matter of minutes. She then set her sights on the X-Men, hijacking Xavier’s body and taking it to the Shi’Ar where she caused even more damage. Eventually, the X-Men were able to move Nova’s consciousness into the body of Stuff, a member of the Imperial Guard, and imprisoned it in the basement of the mansion.
Cassandra Nova has gotten out a few times to trouble the X-Men in the past, and even tried to lead a mummudrai invasion of Los Angeles against Storm’s X-Force team a few years back. But her return in X-Men Red has been the biggest offensive she’s launched against mutants since her genocide in Genosha at the start of Grant Morrison’s run on New X-Men.