The series Marvel Cinematic Universe (MCU). The series has introduced the fact that Wanda is the Scarlet Witch, possesses Chaos Magic powers, and has the ability to change reality into anything she wants, and she doesn't even know how she does it.
Wanda has faced off with Agatha Harkness, one of the most powerful witches in the world, and even she said Wanda is so powerful that she poses a great danger to the world. This is concerning, but the MCU has already introduced one powerful wizard, as Doctor Strange is the Sorcerer Supreme and Scarlet Witch will be in his next movie.
It Could Bring In Mephisto
The biggest rumor in WandaVision is the villain behind all the events in the series is Mephisto. The thing with Mephisto is, he grants wishes to people and allows them to achieve their dreams in exchange for something.
While Wanda created this entire town on her own without asking for anything, there is always the chance that Mephisto could still be granting people's dreams to come true in exchange for watching the world burn. Doctor Strange is a major Mephisto nemesis.
It Could Bring In Nightmare
The other idea, and one that makes more sense after watching both the origin of Agatha Harkness and Scarlet Witch, is Nightmare is pulling the strings.
There has been a lot of symbolism throughout WandaVision, and it was Wanda's fears and distress at all her dreams falling apart that made her create Westview in a sitcom image. Having Nightmare orchestrating everything could explain it all, and he is a lot more closely related to Doctor Strange than even Mephisto.
Doctor Strange Could Train Her
While Agatha Harkness was made out as the villain in WandaVision, that is not likely as accurate as one might think. Yes, Agatha dealt in the dark arts, but she was never doing anything overly evil in WandaVision other than trying to find out what she was dealing with concerning Wanda.
There is a good chance that Agatha could help train Wanda when all is said and done, but there is also a chance Wanda could go to Stephen Strange for help, as he is much more likely to teach her right from wrong than Harkness.
Doctor Strange Could Call For Help
Agatha Harkness told Wanda she was the Scarlet Witch and her magical power is called Chaos Magic. This is the most powerful magic in existence and was thought to not exist outside of legends. However, Wanda uses it, and that makes her extremely powerful.
Doctor Strange in the Multiverse of Madness is still a year away, and that gives Wanda time to hone and master her magic, especially if she trains with Agatha Harkness. If Strange is in dire straits in his movie, he could call on a powerful ally for assistance, and no one is more powerful than the Scarlet Witch.
The Multiverse Could End Up Broken
Wanda has done a lot to change things in Westview, and with Chaos Magic, she could rewrite all of reality. She could also theoretically open up a wormhole that breaks the Nexus of all Realities, which could cause different worlds in the multiverse to leak into others.
There is a reason the word Multiverse is in the new Doctor Strange movie title, and if Wanda is who breaks the Nexus, then it could be up to Doctor Strange to fix it.
Doctor Strange Has To Stop Her
There is a chance that Wanda Maximoff could break completely. If she has her children taken away and then the entire dreamlike town she created is destroyed, it could shatter her worse than she was before.
The Scarlet Witch is powerful, and there is no way even someone like S.W.O.R.D. could stop her. If Wanda ends up on the loose and on the run, it could be up to Doctor Strange to find and bring her in, if only to help her.
Doctor Strange Has To Clean Up Her Mess
There is a running theme in the comics; Wanda does something, and then Doctor Strange has to come in and clean it up. He actually does this for a lot of people, with Spider-Man needing his help more than once. He will be in Spider-Man: No Way Home, likely to clear up Peter Parker's latest mess.
After that, it could be time to clean up Wanda's mess. He has had to undo many things she did in the past, the most recent sending back zombie mutants she raised from the dead. Could Wanda accidentally do something bad that Strange has to fix?
They Face Wundagore Mountain
There is not much in the MCU about Wundagore Mountain yet. That is where Wanda and Pietro were raised in the comics, and it is the base of the High Evolutionary. He gave Pietro his powers through genetic testing and was thought to give Wanda hers as well.
The people of Sakovia were said to have abnormalities Hydra was interested in, which feels similar to Wundagore. There is always a chance Strange and Wanda goes to Wundagore/Sakovia to discover how she got her powers.
The MCU Disassembled
Wanda was involved in two major storylines back-to-back in Marvel Comics that showed how powerful she really is. The first was called "Avengers Disassembled."
In this story, Wanda had previously had her twins erased from her memory by Agatha Harkness. However, something triggered the memories, and she went crazy, destroying the Avengers and murdering Agatha Harkness. This also resulted in Hawkeye and Ant-Man's deaths, and it took Doctor Strange to come in to stop her.
Wanda Creates Mutants
The second event should sound very familiar to fans of WandaVision; in House of M, Wanda woke up from being shut down by Doctor Strange, and she created a brand-new reality. Instead of just one town, she re-created the entire world. She erased racism and gave the mutants a chance to live in peace. She made everyone's dreams come true.
However, she had to be stopped because she was controlling everyone. It ended with Wanda saying "no more mutants" and stripping almost all of them of their powers. If she takes over the world after the events of WandaVision, could she end it by doing the opposite and creating mutants?