Introduced in: House of M #1 (2005)
Following the events of Avengers: Disassembled and Scarlet Witch’s mental breakdown, Wanda was taken in by Magneto to help her heal. However, several months passed and the X-men and Avengers gathered to discuss a solution to Wanda. Attending the meeting and believing that the heroes planned to kill his sister, Quicksilver raced to his sister and convinced her to change the world for her own benefit. Using her powers, Wanda transformed the world into the House of M universe, a world where mutants were the dominant species and normal humans were persecuted.
In this universe, a racial war broke out between humans and mutants during the 19th century. Mutants were losing the war as they had no leader to guide them. Then came Magneto who led the mutants and would eventually win the war, alongside his friend Xavier. He would become the king of much of the world and would bring peace to many mutants. Decades later, Wolverine and Layla Miller realized that this wasn’t the way that this world was supposed to be and began looking into why it came about. Using Layla’s powers, they awoken many heroes and mutants to the truth. They would begin working with the human resistance to defeat Magneto, believing he caused this world. When it was learnt that this was Quicksilver’s fault, Magneto turned against his son and killed him. Seeing this caused Wanda to have another breakdown and utter the famous world, “No More Mutants” and transformed the world back to normal. But of course, this universe would continue after the restoration.