Wanda Maximoff is considered to be arguably the most powerful Avenger, and not without reason.
With more and more disturbing details emerging about the Scarlet Witch's atrocities in 'Doctor Strange and Multiverse of Madness', fans start to question whether Wanda's killing spree in the movie actually created a major MCU inconsistency.
In Earth-838, Wanda was quick and surprisingly okay with killing the entire group of the Illuminati, who served as the Earth's mightiest heroes in that dimension. The team in fact killed Thanos in that universe, which John Krasinski's Reed Richards broke down when speaking to "our" version of Doctor Strange.
Wanda easily tackled the group, as it only took her 5 minutes to kill everyone. So why wasn't she able to defeat Thanos, whom the Illuminati destroyed – seemingly with his own weapon?
What seems to be a major plot hole at first does in fact does have a logical explanation. At the time when Wanda had to face Thanos in a battle, she wasn't in possession of the powers provided by Darkhold, nor did she have any idea regarding her being the Scarlet Witch.
Still, even without those powers, it was challenging for Thanos to withstand a face-off with Wanda. In 'Endgame', he even had to sacrifice his own army in order to break free from her magic.
Although many people already thought about how useful the Darkhold powers would be in the fight with Thanos, they did not turn out to be well for Wanda. Corrupted by the dark magic, she has turned into a villain in 'Multiverse of Madness', even though she ended up realizing she was wrong at the end of the movie.
The fate of Scarlet Witch remains unclear as she buried herself under the ruins of the Wundagore castle. The studio is yet to clarify whether Elizabeth Olsen's heroine is to return in any other Marvel projects.