In Captain America: The Winter Soldier's post-credits scene, we learned that HYDRA had used Loki's sceptre to create Quicksilver and the Scarlet Witch.
WandaVision later revealed that their use of the Mind Stone simply unlocked what was already there in Wanda Maximoff. However, in Avengers: Age of Ultron, the twins were introduced as antagonists (with 20th Century Fox holding the rights to the X-Men franchise at the time, they served Ultron, not Magneto).
Just like their comic book counterparts, Wanda and Pietro ultimately saw the error of their ways and joined the ranks of The Avengers. Quicksilver sacrificed his life to save Hawkeye, but the Scarlet Witch suited up as part of Captain America and Black Widow's new team.
Thanks to X fan account @wandasattorney, we have some never-before-seen shots of Elizabeth Olsen suited up as the Scarlet Witch. This costume didn't carry over from Avengers: Age of Ultron to Captain America: Civil War, but remains a popular look for the character.
Last September, Jimmy Kimmel caught up with Elizabeth Olsen and asked if the hero-turned-villain really is dead. "I think so. I assume as much. Yeah, and there was a red light of explosive energy. I think I'm dead," she replied. "I would beg to leave a window open. I had so much fun doing these movies. I would like to figure out how to cleverly be undead."
"We need to find the smartest writers to figure out how to make this all make sense. I'm open to ideas," Olsen added.
In the same conversation, Kimmel put it to the His Three Daughters star that the Scarlet Witch is arguably more powerful than Thor. "I think I am. I think theory has it that Wanda could beat him," she acknowledged. "I don't know...I've never played with the hammer, I don't think...yet. I don't know if that's happened actually. I think I could probably somehow manipulate and go inside his body to do the same thing he does."
The expectation is that Wanda will return in Avengers: Doomsday and Avengers: Secret Wars, potentially as an unwitting pawn in Doctor Doom's mission to "save" the Multiverse. Olsen's role in those movies hasn't been confirmed, and it's possibly being saved as a surprise in the two-part Multiverse Saga finale.
Check out these new shots from Avengers: Age of Ultron in the X posts below.