The following contains spoilers of Doctor Strange in the Multiverse of Madness, currently in theaters.
When thinking of the effect of Doctor Strange in the Multiverse of Madness had on Wanda Maximoff, two words come to mind: "character assassination." The Scarlet Witch comes out the other end of the film soaked in the blood of her enemies, buried in the ruins of a once-promising character arc. Whether she's actually dead remains in question, as her sacrifice at the end of the film feels deliberately vague, but the character of Wanda as fans knew her is gone forever.
WandaVision made a deliberate effort to bring Wanda to a place of villainy, but never actually make her the villain. The mystery surrounding the Hex and what caused it obscure her culpability for most of the show, and even once she fully claims responsibility, the role of primary antagonist is taken by Agatha Harkness. She's left a morally complex character, having harmed plenty of people but with little permanent impact. She doesn't kill en masse, and the collateral damage she causes is mostly psychological damage and trauma. She is guilty, but only of crimes the audience can understand and forgive.
At first, Multiverse of Madness seems to follow in the same mold, with Wanda as a sympathetic ear to Stephen's difficulties in defending America Chavez. She acknowledges the harm she did in Westview, but even Strange points out that she took every step possible to try and repair that harm. It's only at the end of the scene where that facade slips away, revealing Wanda to be the primary antagonist of the film, and her goal is to kill America Chavez. It's not just to make use of her power -- it's pointed out she could just force America to open a gate, but she's going to kill Chavez so that if she ever needs her power again, it's right at her fingertips.
With that, Wanda proceeds to go on a killing spree,murdering not only the guardians of Kamar-Taj but countless bystanders in her quest for power. A good chunk of the second half of the film has her covered in blood, after a particularly brutal scene in which she defeats the Illuminati single-handedly. More than anything else, it's this utter disregard for the lives of others that marks her character. She accuses Strange of hurting others in the name of "necessity" to save the universe from Thanos, but his intent was just that -- to save the universe. Both are willing to do whatever is necessary to achieve their goals, but her goals are to take a pair of children away from an alternate version of herself -- his were to save the universe.
This corruption of Wanda's character also feels sudden, unexpected and unearned. She was seduced by the Darkhold, driven to terrible ends by the grief she feels over the loss of her children. That sounds good, but in no way justifies her desire to kill a teenage girl. Wanda's desire to be reunited with her children never provokes any amount of empathy for Chavez, who is separated from her own parents. In fact, a happier ending could have seen Wanda teaching Chavez to control her powers, finding peace in caring for a child who does exist in her world.
However, Wanda only stops her bloody rampage when she sees how she's scared her children. She brings the citadel atop Mount Wundagore down while she's still inside it, a tomb of her own making. It's a sad ending for a character many fans had come to love over the years, and far less than what she deserved. Even if she survives to see another appearance, she's been forever changed by the horrors and atrocities she's committed.
Questions of what it means to seek forgiveness and to find peace were already an option for Wanda from the end of WandaVision. Multiverse of Madness chooses not to explore those ideas, and instead advances her down the darkest of paths, changing a Wanda with shades of gray to a character soaked in bloody crimson -- a Scarlet Witch.
To see Wanda's change, Doctor Strange in the Multiverse of Madness is in theaters now.