In Avengers: Disassembled and the subsequent House of M, Wanda loses her grip on reality, as well as her powers. Not only does she cause the deaths of Ant-Man and Vision, but she gets Hawkeye killed twice.

With just three words, "No more mutants," she depowers 99.9% of the mutant population, renouncing once and for all Magneto's philosophy of mutant superiority. Her spell is so complex and binding that not even Dr. Strange himself dares attempt to undo it.

In Uncanny Avengers #14, Wanda meets her death at the hands of her teammate Rogue, who has absorbed Wolverine's powers. This death is eventually undone when the surviving Unity Squad are projected back in time, having learned that Rogue was manipulated by the Apocalypse Twins into killing Wanda, allowing the Avengers to band together and defeat an approaching Celestial.

When the twins were reabsorbed into Mephisto, because of the power Wanda had injected into the demon's soul fragments, they destroyed him, and the twins were reincarnated as the Young Avengers Speed and Wiccan.

After his reality-altering powers begin spiraling out of control, Wiccan sets out to find the one person who may be able to help him--the woman purported to be his mother. When he finally tracks her down in Latveria, the Scarlet Witch not only has no memory of who she is, but she's engaged to Doctor Doom.

Of all the demons in the Marvel Universe, none is more powerful than Chthon, who altered Wanda at birth and gave her the ability to use chaos magic in addition to her mutant abilities, planning to use her as a vessel when her powers reached maturity. Fortunately, Doctor Strange is later able to help free her from Chthon's control.

The Scarlet Witch has the honor of being created by Stan Lee and Jack Kirby--the legendary writer/artist team responsible for the majority of the Marvel Universe.