Scarlet Witch's History
Born at the Wundagore base of the High Evolutionary, Wanda and her twin brother Pietro were eventually placed in the care of a Gypsy couple named Django and Marya Maximoff, from whom they were separated as teens when their encampment was attacked. They were later recruited into Magneto's Brotherhood of Evil Mutants and, as the Scarlet Witch and Quicksilver, they fought the X-Men. At the time, none of the three were aware of the siblings' paternity. They soon abandoned their terrorist activities, while Magneto was imprisoned by the Stranger, and joined the Avengers. The remaining founding members had all gone on a leave of absence, leaving Captain America to lead an all-new lineup including Wanda, Pietro, and the archer known as Hawkeye. Although she became more adept in her power's use, Wanda did not realize that she was tapping into genuine magic. It was believed that the Scarlet Witch would have been an ordinary energy manipulator or perhaps simply able to cause bad luck if not due to Chthon's attempt to use her as a pawn.
Wanda fell in love with the synthezoid Vision, an artificial being created by Avengers foe Ultron who joined the team rather than fight them. The Scarlet Witch eventually married her teammate, the android Vision, not realizing that they were manipulated by Immortus, who sought to prevent Wanda from having a child (Wanda was actually a key figure, or nexus being, to her reality, and her children would have power to shake the foundations of the universe). Wanda eventually drew on magic energy to give birth to twin sons, William and Thomas, but this energy was eventually revealed to have come from the demon Mephisto, who reabsorbed them, effectively ending their existence. Wanda had also reanimated her deceased mentor, Agatha Harkness, through whom she cast a spell to make her forget her children in order to ease her pain. Though Wanda later recalled her loss, she suppressed this memory over the long term. After his reformation, The Vision and Wanda have not had the closeness they once did.
While both were serving as members of the Avengers West Coast, Wanda also grew to love Wonder Man, the man whose brain patterns had been used to form the Vision's mind. Both were among the former AWC members who opted to form Force Works after the team's dissolution. As the leader of this new team, Wanda used a 'hex mainframe' computer designed by Iron Man. Through her powers and the computer's calculations, they could proactively determine where the team was most needed rather than react to an alarm or breaking news. Although Wanda was appointed team leader, she often clashed with Iron Man overriding her orders. She was deeply saddened by Wonder Man's death on the first mission of Force Works. After rejoining the Avengers, she used her increased powers to resurrect him, although his ionic energy likely made him able to be restored. For some time, Wonder Man was mostly a cloud of ionic energy that Wanda had to summon.
Training with Agatha Harkness increased Wanda's control of her 'chaos magic.' Even after Agatha died her astral form continued to assist Wanda. However it seems that at least some of this training may have been an illusion made by Wanda herself.
In years after, Wanda remained in her role as a longtime Avengers mainstay, salvaging her relationship with the Vision as best she could - although sparks also appeared with Captain America towards the end of her Avengers tenure - the moment she brought the team to its lowest moment ever recorded.
An unintentional remark by team-mate the Wasp about Wanda's lost children apparently drove her over the edge. Her various manipulations caused a number of her Avengers teammates to be killed. Others were injured or affected by various odd outbursts and incidents. The remaining Avengers gathered including a number of reservists. However, it appears some of them were more illusions created by Wanda. Doctor Strange appeared, sensing abuse of magic, and angry that he had not been notified of Wanda's recent problems.
The Scarlet Witch seemingly gained powerful reality-altering abilities from "Chaos Magic"; however, this proved to be an uncontrolled aspect of her mutant power and created a great mental strain on her. When vague memories of her children resurfaced, she suffered a nervous breakdown and lashed out with her new power, subjecting the Avengers to a savage assault and apparently killing Agatha Harkness and some of her teammates. Strange was forced to use the Eye of Agamatto on Wanda, which apparently showed her a memory so horrible she went into a catatonic state. Magneto suddenly appeared to collect his daughter, and brought her to Genosha so Professor X could help her.
Unfortunately, Xavier refused to do so as Wanda attempted to restore her husband to life and undo the damage she had caused. Keeping Wanda in a comatose state, Xavier ultimately called a meeting between the Avengers and X-Men to decide whether or not Wanda should be killed. Quicksilver was horrified at the fact that Xavier seriously considered killing Wanda and convinced Wanda to take desperate action to keep this from happening: By using her powers, Wanda warped reality into the House of M, a world where mutants were the majority, humans the minority, and Magneto the ruler (simultaneously giving various other heroes what they wanted most, hoping this would prevent them rebelling). In this reality, Wanda was believed to be a human, due to an alternate body she created to represent her in public while she cared for her children in private.
A young mutant named Layla Miller (whom Dr. Strange believed was actually an aspect of Wanda's psyche, but later revealed to be a deformed mutant who was given a normal body thanks to Wanda's reality warp) was able to use her mutant abilities to restore several of the heroes' memories. Meanwhile Wolverine (the only person who sensed the reality's "wrongness") and a resurrected Hawkeye (who had been seemingly killed during Wanda's breakdown) and Cloak gathered these heroes into an assault force to try to restore reality. This rag-tag army headed to Genosha to attack Magneto, believing him to be the one responsible for the change. During the battle between Magneto's forces and the others, Layla was able to restore Magneto's memories; as well, Wanda confessed to Dr. Strange that it was Quicksilver, not Magneto, who had initiated the reality warp.
Enraged, Magneto confronted Quicksilver, angry that Quicksilver had done all of this in his name. Quicksilver told Magneto that he would have let Wanda die. Magneto replied that Quicksilver had only used him and Wanda. He then killed Quicksilver. Wanda revived her brother, telling Magneto that Quicksilver had only wanted him to be happy and that Magneto had ruined them, choosing the mutants over his own children. She further denounced Xavier and in three words ("No more mutants") Wanda changed the world back to its original form but adding the mass depowering of 90% of the entire mutant population, thus being responsible for many deaths as shown in the Generation M mini-series. Surviving mutants and ex-mutants now refer to this as "M-Day: The worst day in mutant history."
After the fallout, Wanda was missing and was last seen in a small, unknown European village, happy and in a state of peace.
The resurrected Hawkeye (Clint Barton) tracks Wanda to a small village near Wundagore Mountain, where he unknowingly saves her from a thief. Wanda has been living in a small apartment with her only relative, her "Aunt Agatha" (who is never seen, but could possibly a manifestation of Wanda's now-dead mentor Agatha Harkness). She appears to be powerless and believes that she has lived her entire life in the village, and does not recognize Hawkeye, nor does she remember being a part of the Avengers or other events. Wanda tells Hawkeye that he was her "hero" for dealing with the thief and kisses him, and they spend the night together. The following morning, while Wanda is sleeping, Hawkeye becomes curious about the next room where "Aunt Agatha" is supposedly sleeping, but the doorknob appears to shift away from his hands, a subtle reality manipulation usually associated with the Scarlet Witch. However, Clint looks back to see that Wanda is still asleep.