Scarlet Witch (Elizabeth Olsen) is the most important hero in Phase 4 of the Marvel Cinematic Universe. Wanda Maximoff initially debuted as a villain in Avengers: Age of Ultron alongside her brother, Quicksilver/Pietro Maximoff (Aaron Taylor-Johnson). By the end of the same film, the Avengers embraced her as one of their allies, even joining the team full time. Since then, she's become one of the good guys.

Comic book fans were excited upon learning that Marvel Studios was introducing Scarlet Witch into the MCU. Known for her immense power set in the comics, people were looking forward to how she'll change the franchise's power structure. Unfortunately, they initially failed to flesh out the character, relegating her to a supporting role when she could've easily been one of the universe's most prominent players. This is partly due to the focus being mainly on the original six Avengers - particularly Iron Man (Robert Downey Jr.), Thor (Chris Hemsworth), and Captain America (Chris Evans). For what it's worth, this makes sense as the franchise was building towards sending off some of those heroes off in conjunction with the end of the Infinity Saga. But there was still a lot of missed opportunities in giving Scarlet Witch a bigger place in the universe.

Things are starting to change, however. Based on what's been revealed about MCU's future thus far, Wanda is set to play an important role in Phase 4 with confirmed appearances on the big and small screen. She will first return in the Disney+ series, WandaVision - a sitcom-inspired show with a comic book flare in it, the project will reunite her with her Vision (Paul Bettany) as they live a seemingly perfect suburban family life. Arguably the most interesting project from Marvel Studios' upcoming TV efforts, the brief footage from the show reveals Wanda front and center of the narrative. Depending on the scheduling, WandaVision may also be Marvel's inaugural series for Disney+, especially since The Falcon and the Winter Soldier still has overseas filming left in the Czech Republic which is trickier to finish considering the ongoing coronavirus pandemic.

After starring in her own TV show, Wanda will return on the big screen, joining Doctor Strange in the Multiverse of Madness. The Sam Raimi-directed film is set to have a narrative connection with WandaVision, so Scarlet Witch's involvement in the sequel is somehow expected. Aside from that, partnering her up with a sorcerer like Stephen Strange makes sense considering their similar power sets. If anything, Strange could mentor Wanda and help her control her abilities better. This could be a stepping stone for the character to become one of the faces of the franchise - even leading her own movie moving forward.

The narrative connection between the projects could mean the multiverse will also play a factor in WandaVision. This is something that has already been theorized seeing how the show's teaser reveal different versions of its titular characters from different eras. As fans know, the MCU will fully dive into the multiverse come Phase 4 with Avengers: Endgame already creating a branched reality that will be tackled in Loki. Chances are this is only the beginning of their endeavor to expand to other timelines, resulting in the multiverse defining the franchise's future. Between Scarlet Witch's involvement in both projects and her supposed ability to alter reality, fans can expect her to be one of the key players at the center of the MCU's efforts to establish its multiverse moving forward.

Finally, Scarlet Witch could serve as the bridge in incorporating the X-Men in the Marvel Cinematic Universe. After Disney's historic acquisition of Fox's TV and movie assets, Marvel Studios received the creative rights to the mutants, Fantastic Four, and their tie-in characters, meaning their arrival in the MCU is imminent. While Marvel Studios tweaked Wanda's origin story - sourcing her powers from the Mind Stone rather than being a mutant like she is in the comics, there's a narrative opening hinting that this can still be retconned so Scarlet Witch could become a latent mutant instead.