At least a few key characteristics and potential plot points will be kept from Scarlet Witch's history in the books, at least it seems that way from Olsen's description of the character:
"I just love Scarlet Witch. I love her. It's so funny because I'm often talking about all these psychologically damaged people, but when you talk about Scarlet Witch... She is a messed up lady. She has got more sh*t to deal with than anybody else I know. I'm excited to figure out what's appropriate to use for her, because there's so much material from all of these decades, and we're going to tell this one story. So to be able to choose what you're going to bring into it from all of this abundance, it's really fun."
Scarlet Witch and Quicksilver have a troubled history, switching sides from "hero" to "villain" by association (their father is X-Men villain Magneto) on multiple occasions. If the character is "messed up" in in the film, we're curious how she and her bro meet The Avengers, why they sign up, and what their connections are with the new origins of Ultron. Joss Whedon is introducing the pair for very specific story reasons and while we know Scarlet Witch and Quicksilver don't necessarily agree with what The Avengers do, there are some very interesting story implications of an unpredictable, super-powered and potentially psychologically damaged character like Scarlet Witch - especially considering her odd relationships.
Ultron, a sentient AI, created another android character named Vision in the comics - the husband of Scarlet Witch and another Avenger. In the Ultimate Marvel Comics stories of The Avengers, it's Ultron who actually kills Scarlet Witch (who in this version has an overly loving relationship with her brother) so there are definitely some dark times ahead, as Whedon has suggested in the past when saying "awful" things will happen to the team.
Let us know in the comments what you'd like to see from Quicksilver and Scarlet Witch's costumes, powers and relationships in the Marvel Cinematic Universe!
The Avengers: Age of Ultron is written and directed by Joss Whedon, starring Aaron Taylor-Johnson, Chris Evans, Chris Hemsworth, Cobie Smulders, Elizabeth Olsen, James Spader, Jeremy Renner, Mark Ruffalo, Robert Downey Jr., Samuel L. Jackson, and Scarlett Johansson.
Captain America: The Winter Soldier on April 4, 2014, Guardians of the Galaxy on August 1, 2014, The Avengers: Age of Ultron on May 1, 2015, Ant-Man on July 31, 2015, and unannounced films for May 6 2016, July 8 2016 and May 5 2017.
Follow Rob on Twitter @rob_keyes for your Marvel movie news!
Scarlet Witch header art by Rick-4F