Whenever Robert Downey Jr.'s Tony Stark, also known as Iron Man gets into a scene, he inevitably steals the show. In Marvel's next movie "Captain America: Civil War," his character will play a very interesting role, since he will be going head to head against his good friend and fellow Avenger Captain America in searching for Bucky Barnes.

When asked by Empire if he will be taking on the mantle of the bad guy, Downey answers: "I wouldn't put it that way. Ultimately it's Steve's story; it doesn't say 'Iron Man 4: Civil War,'" although he jokingly added, "I think that's great too."

One of the things people can expect from "Captain America: Civil War" is that the Avengers' leader, Captain America, will be taking on an even more authoritative stance. Downey noted that Chris Evans, who plays the title superhero has been "hungry" to develop that side of Captain America, and to "bring even more of an underside and some shadow to that."

"I remember the comics - on the surface you got the sense that Cap was baseball and apple pie, but underneath there was all this churning stuff of being a man out of time," said Downey. "Now we know he's made his peace with that. What's the bigger issue? It can have a little something to do with the past, but it can be about someone becoming more modernised in their own conflict."

Downey is trying to be cryptic in his answers, but it looks like the Avengers will be in over their heads as they try to search for new weapons to use in defeating their enemies. Stark being Stark will be quite the rogue if he decides to pursue vengeance despite the intentions of his fellow Avengers, and Downey teased that his character's future direction is already quite evident in "Avengers: Age of Ultron."

What fans have to focus on is Stark's motive, he explained, since that would reveal why he would "completely turn around everything he's stood for."

"The idea of Tony being able to march into Washington and say, 'I'll sign up', wouldn't have made sense if the political climate in the real world hadn't shifted the way it has. It's a little bit of things following a real world continuum in, 'What would you do?' You have to figure, 'Were you to ask the question, what would the American government do if this were real? Wouldn't it be interesting to see Tony doing something you wouldn't imagine?'" he said.