Decimation (comics)

"Decimation" is a 2005 Marvel Comics crossover storyline that follows the aftermath of the House of M series. It begins with the one-shot issue titled Decimation: House of M – The Day After, written by Chris Claremont, and illustrated by Randall Green and Aaron Lopresti, released on November 9, 2005. The storyline then unfolded across multiple tie-in issues and series, all featuring the "Decimation" logo on the cover.

The name "Decimation" refers to Wanda Maximoff/Scarlet Witch’s act at the end of the House of M limited series, in which she utters the phrase "No more mutants". This rewrites the Marvel Universe by depowering the vast majority of mutants. This event is also referred to by several names in Marvel titles, most notably "M-Day". The titles and issues focus on a select range of characters across the Marvel Universe, including the X-Men, New X-Men, Excalibur, X-Factor Investigations, New Avengers, and more, as they adjust to the loss of their powers.

At the conclusion of the House of M limited series, Wanda Maximoff utters the phrase "No more mutants". This act dissolved the alternate "House of M" reality (designated Earth-58163) and snapped the universe back to the core Marvel reality, Earth-616, but with its fabric permanently rewritten. This act, dubbed the "Decimation", is a reality-altering "spell" that rewrote the fabric of the Marvel Universe. It depowered existing mutants, suppressed the mutant gene, the "X-gene", and prevented the birth of new mutants for years, ultimately reducing the mutant population from millions to fewer than 200.

The "Decimation" served as the basis for the storyline crossover even that examines the fallout from the "House of M" event. It is an arc that allowed Marvel to regain control and reconstruct X-Men title continuity while also returning X-Men to their original state as alienated and feared outsiders.

Throughout different Marvel Comics, "Decimation" is also referred to by several alternate names, including: "M-Day"; in Generation M, "Mutant Decimation"; in Avengers: The Children's Crusade, "The Great Power Outage of 2005"; in X-Factor, "The M-Day Decimation"; in X-Men: Legacy, and "Wandageddon"; in Way of X.

The "Decimation" storyline began with the self-titled one-shot Decimation: House of M: The Day After, it heralded the relaunch of the Excalibur team in New Excalibur, focusing on Pete Wisdom looking for Captain Britain to head up a new British super team, as well as the relaunch of X-Factor from the MadroX miniseries. It also includes several mini-series—Son of M starring a depowered Quicksilver, Generation M focusing on other depowered characters, Sentinel Squad O*N*E showing the latest iteration of the mutant-hunting Sentinels to be robots piloted by humans, X-Men: Deadly Genesis, and X-Men: The 198—and continues throughout the Marvel Universe, particularly in the X-Men-related titles. One consequence is an upswing of anti-mutant sentiment, especially among certain religious groups, who consider M-Day to be God's judgment against mutant-kind.

It has been confirmed through various sources that there are considerably more than 198 mutants remaining—the number has been referred to as "symbolic" rather than actual, and in The 198 Files is said to be the earliest confirmed number. Numbers for pre-Decimation mutants vary from "over a million" (House of M #8) to 14 million (New X-Men #115, where it is said that the 16 million mutants who died on Genosha was around "over half" of the estimated global mutant population of 30 million mutants), giving a population, if the commonly used 90% depowered figure is true, of between one hundred thousand and one and a half million. Based on the mathematical comparisons of the oft-repeated 198 and several million, Marvel re-evaluated the 90% figure into "over 99%", as shown in Civil War: Battle Damage Report when Iron Man comments on the Post-CW world.

Both Hank Pym and Beast note shortly after the event that it is impossible for the energy that certain mutants controlled to simply have vanished, and that it must have been "sent" somewhere. As would later be revealed in New Avengers, most of this energy became a sentient entity called the Collective, who has since come into violent conflict with the Avengers. In addition, a portion of the energy revived the body of Gabriel Summers, brother of both Alex (Havok) and Scott Summers (Cyclops), who had been trapped in space for many years following the defeat of Krakoa, as depicted in the X-Men: Deadly Genesis limited series.