X-Men: 10 Worst Things The Mutants Have Done
2. No More Mutants
House of M had the Scarlet Witch change reality into a world where mutants were the dominant species of the planet and Magneto and his children ruled the Earth. This forced the Marvel heroes to band together in this alternate universe and restore the world they knew.
In the climax of the storyline, the Master of Magnetism kills Quicksilver after finding out he was responsible for the events that transpired. A grief-stricken Wanda, who realizes that Magneto has placed mutants above his own children, utters the words "No more mutants". Her actions restore the Marvel Universe back to normal, but with severe consequences. A lot of mutants lose their powers, while their numbers are reduced to a few hundred, effectively turning them into an endangered species.
Wanda's actions would cause ripples across the Marvel Universe with villains such as Onslaught and the Shadow King returning because of the new reality. At the same time, the reduction of the mutant community forces Cyclops to take desperate measures, which leads to his schism with the X-Men and his transformation into a mutant revolutionary.