"Necrosha" is a 2009–10 comic book crossover storyline published by Marvel Comics featuring the X-Men family of characters. In the storyline, Selene decides to utilize the techno-organic virus power to bring any deceased mutants back to life, allowing her to begin her quest to ascend to godhood. This prompts multiple mutant teams to fight against Selene in an attempt to free the newly resurrected mutants. The storyline is notable for reviving a vast majority of its characters.

Necrosha had been slowly building in the pages of X-Force and began in earnest with the one-shot X-Necrosha, released on October 28, 2009, and continued in X-Force, New Mutants, and X-Men: Legacy.

Through her servant, Eli Bard, Selene, the Black Queen of the Hellfire Club, gains access to the Technarch transmode virus, which she uses to resurrect dead mutants. This resurrection is the beginning of her plan to become a goddess.

Selene orders her minions to bring Destiny, one of the resurrected mutants, to her. Selene wants to know what her future holds; Destiny tells her she will achieve what she has set out to do, and is put back in her cell again. Destiny insists she needs to do something, that otherwise these events will end badly. Destiny is able to contact Blindfold in Utopia and asks the girl to deliver a message. Destiny believes that she has made a mistake. Selene, however, gets something she did not plan for: another major villain, Proteus, is brought back to life along with the resurrected Destiny.

Selene returns to the place of her birth in central Europe, accompanied by her new Inner Circle, consisting of Blink, Senyaka, Mortis, Wither, and Eli Bard. They then travel to the New York branch of the Hellfire Club, where they slaughter every person there. She targets others who, according to her, have failed her in her quest for godhood, such as Sebastian Shaw, Donald Pierce, and Emma Frost (for whom she has a particular animus for having adopted the "Black Queen" moniker while working for the Dark X-Men). She also intends to attack the X-Men, because they have opposed her many times, and Magma, for her betrayal in Nova Roma. Caliban and Thunderbird lead her to the ruins of Genosha, where she claims her journey will end, welcoming them to what she now dubs Necrosha. She sends most of the resurrected mutants to attack the X-Men on Utopia, and dispatches Cypher to kill Magma.

With Eli Bard, Selene resurrects the massacred residents of Genosha, with Cerebro and Bastion's computers detecting the rise of mutant numbers into the millions. There is a major problem, however: many of the dead have been depowered, despite having been killed before M-Day. The Coven begins to set up a base at Necrosha.

Meanwhile, Cypher sneaks into Magma's room and knocks her unconscious; however, he cannot complete his mission of killing her due to the intervention of his former teammates and the arrival of Warlock. Sensing that something isn't right, Eli Bard reports to Selene what is happening, prompting her to send the Hellions to help and to retrieve Cypher. The former members of the New Mutants team manage to defeat the Hellions, while Magik finds out that her soulsword can damage the mutants revived by the Techno-organic virus. Warlock returns and, in combination with Magik's soulsword, manages to free Cypher from the Black Queen's influence, leaving him restored to life and in possession of his own memories and free will.

Amidst the chaos, a squad of resurrected Acolytes have come for the former White King of the Hellfire Club, Magneto. They fight Loa and temporary X-Man Deadpool, who finds out that Loa's powers can damage the mutants revived by the Techno-organic virus.