After spending the vast majority of her time in the Marvel Cinematic Universe as a supporting character that's been given very little to do, Elizabeth Olsen's Scarlet Witch is poised to become one of the most important parts of the franchise's Phase Four. After all, Kevin Feige is hardly going to change his mind and say Wanda Maximoff has usurped Captain Marvel as the most powerful superhero in the shared universe without having plans in place to back it up.