'Avengers: Age of Ultron' Spoilers: How Different are Scarlet Witch and Quicksilver from the Comics?

Quicksilver and Scarlet Witch are two important characters that have been introduced in "Avengers: Age of Ultron," and director Joss Whedon recently gave fans a hint on what to expect from the superheroes in the next instalment of the "Avengers" movie.

Talking about the challenges into bringing Quicksilver and Scarlet Witch into Marvel Cinematic Universe, writer-director Whedon said the movie presented him with the opportunity of reinventing them.

In the comic series, Quicksilver and his twin Scarlet Witch -- the roles essayed by Elizabeth Olsen and Aaron Taylor-Johnson in the movie -- are mutants who made their debut in 1964's X-Men #4. But because the X-Men movie rights are owned by 20th Century Fox, Whedon was not allowed to use the term mutant in the Marvel Cinematic Universe.

However, this allowed him to introduce the characters on his own terms. "It allowed me to tie their origin into the mythos of this [Marvel Studios] universe more effectively. It's more useful to me than introducing the idea of mutants," Whedon told BuzzFeed.

In the comics, Scarlet Witch's superpowers enable her to change the probability through "hexes," but in the movie her powers are telekinesis and mind control. Her twin, meanwhile, has the capability to run faster than the speed of sound.

The introduction of Scarlet Witch will enable fans to get into the heads of the Avengers, and finally understand their thought process.

"She can make you have a nightmare, is one way of putting it," the director said. "Trip balls would be another one. That was something I very much wanted, because it meant we could spend a little time inside the Avengers' heads, either their past or their impressions of what's going on, or their fears, or all of the above. And confronting that is very debilitating for the Avengers, but it's also kind of revelatory. That's not the movie I made last time. I could never have done that."

"Avengers: Age of Ultron" comes to theatres on 1 May and stars Scarlett Johansson, Robert Downey Jr., Chris Hemsworth, Chris Evans, Cobie Smulders and Jeremy Renner among others.