Following the appearance of the Maximoff twins in the "Captain America 2" post-credits and inclusion in "Avengers 2: Age of Ultron," will there be a cross-franchise with "X-Men" featuring the characters?

New "Avengers: Age of Ultron" star, Elizabeth Olson, cast to play the Scarlet Witch, is an important character in the Marvel Comics. According to Enstarz, Scarlet Witch's twin, Quicksilver, has already been featured in both "Avengers" and "X-Men" movies, so many are hoping that Scarlet Witch would appear in the "X-Men" series as well.

For those who are not familiar with the twin characters' story line, Scarlet Witch and Quicksilver, known as the Maximoff twins, are the children of super mutant, Magneto. Scarlet Witch is able to manipulate energy while Quicksilver is able to move at supersonic speeds.

The two mutants, per IGN, are "long-standing members of the Avengers ever since the controversial Avengers #16 in 1965" making them suitable additions to the set of superheroes. However, since the "X-Men" franchise is under the control of Fox and not Disney, there must have been a limitation to the story line.

"Disney can use the characters, but they can't reference their status as mutants or anything else that would directly acknowledge the X-Men franchise," continued the site. It would be interesting to see how the upcoming "Avengers: Age of Ultron," set for release May 1, 2015, will shed light on the twin's characters.

We'll have to stay tuned for more cast updates on "X-Men: Apocalypse", which drops in theaters May 27, 2016.

'Avengers: Age of Ultron' Update

In the upcoming "Avengers" sequel, the newly released official synopsis makes mention of the twins as "mysterious and powerful newcomers"

Director Joss Whedon also talked about the challenge Scarlet Witch and Quicksilver pose to the Avengers to Entertainment Weekly, "They're on Team Ultron, which makes things really hard for the Avengers because all of a sudden they're dealing with powers that they're not used to," said Whedon.

Unlike other enemies, Scarlet Witch "can get inside your head and move objects, and a boy that can move faster than anything, and a robot [Ultron] who can self-replicate and is out of his mind. So all of sudden, it's a darker, weirder, tougher world that they're living in."

One thing's for sure, Olson is excited about the superhero character. She shares she attacks the process the same way she would in other real-world character roles, writes Screen Rant.

Olson has done a lot of reading and "...it's really exciting. But the imagination, like to a child, and like running around in a play yard is what it feels like right now. And that sounds like so much fun, but you still want to approach it with the same kind of like 'No, this is where she's from,' and it's real."

She continued: "And that's what's fun about it. Let them put on the costume or do the special whatever-they-need-to-do to make it look special, but I'll just do my part - it just has more extreme things to it. [Laughs] I'm like really excited about Scarlet Witch."