The following contains spoilers for Doctor Strange in the Multiverse of Madness, now playing in theaters.
Doctor Strange in the Multiverse of Madness redefined the power levels of heroes and villains in the Marvel Cinematic Universe on a massive scale, but rather than see this through implied means, it was shown firsthand thanks to the sheer chaotic force of The Scarlet Witch's power. While her strength was displayed throughout the film, it was best demonstrated during her battle with The Illuminati, specifically, Captain Marvel, but how did Wanda defeat someone who was empowered by an Infinity Stone?
During the film, Doctor Strange and America Chavez were transported to Earth-838, where they encountered a unique super-team known as The Illuminati, made up of Professor Charles Xavier, Black Bolt, Reed Richards, Baron Mordo, Captain Carter and Captain Marvel (Marie Rambeau). This team was made to make the hard decisions to ensure the safety of the multiverse. A great example of this was through their decision to kill their reality's Stephen Strange and vote on the fate of Earth-616's Stephen, but the latter never came to pass as Wanda, controlling a variant of herself, led a rampage through the facility.
According to Twitter theorist Mastertainment, it was Wanda's dark magic that ultimately gave her an edge over the team's strongest members, which began with the death of Black Bolt. After she dispatched the other heroes, she faced off with Captain Marvel, whose powers were comparable to Wanda's in terms of force and strength. In Earth-616, Carol Danvers showed immense power at her base level, capable of plowing through enemies with little effort on her part. However, when she activated her binary form, she could fly straight through whole spaceships with no damage to her body.
While Captain Marvel in any universe had strength on their side, they also had some absorption. Like the comics, Captain Marvel could absorb any form of energy and redirect it at an opponent, as well as their own stores, but when facing Wanda, they were faced with something far more unique and deadly.
Because of the dark magic that gave her strength and emanated from her body, Wanda was equally capable of absorbing power as well. Furthermore, her chaos magic also tipped the odds in her favor by nature. As a result, she could absorb Maria's light energy, so any chance of her going binary was nonexistent.
Because her power was siphoned off in such a short amount of time, Marie was heavily weakened. Wanda unleashed her final attack that collapsed a statue on Maria and killed her; it was only possible because she didn't have the strength to properly defend herself. In reality, their strongest player, Black Bolt, was the only hope The Illuminati had to defeat Wanda, but because he was eliminated first, she could wipe the floor with the team.
Captain Marvel is still one of the strongest fighters in the MCU, no matter the universe, but because Wanda's natural power automatically gave her an edge, there was no chance she would lose. Nevertheless, it still showed that those powered by an Infinity Stone could still put up a valiant fight even in a weakened state. However, in the end, it was shown that more powerful magic could top cosmic energy from beings that aren't celestial in nature.
To see Wanda defeat Captain Marvel, Doctor Strange in the Multiverse of Madness is currently playing in theaters.