If you're a fan of Robert Downey Jr. (who isn't?) and can't wait to learn more about Captain America: Civil War, you've come to the right place.

Downey Jr., who plays Tony Stark a.k.a. Iron Man in the Marvel films, recently sat down with Empire Online for a lengthy interview about everything Marvel. He covers plenty of topics in the full interview, from meeting The Vision in the upcoming Avengers: Age of Ultron to his reaction at the news that Joss Whedon might not be directing the two-part Avengers: Infinity War and much, much more. Be sure to check out Empire for the full interview for all the details. But perhaps some of his most interesting comments are about his role in Captain America: Civil War.

For example, why did Downey Jr. decide to sign on for the film? In short: Chris Evans.

"I'm crazy about Evans," Downey Jr. says. "I really am. I don't know why or how to explain this particular kinship we have. By the way, he hasn't called me in six months. Honestly, in order for this whole thing to have worked, I did my part, Hemsworth knocked it out of the stadium and then it fell on Cap. That was the riskiest. It was the one that had the highest degree of difficulty in making it translate to a modern audience. It was the Russos and Chris who, I think, really hit the line drive and won the series. I remember glancing through it going, 'Wow, that's a different way to go'. They said, 'If we have you, we can do this or Cap 3 has to be something else.' It's nice to feel needed."

He also talked about Stark's role in Civil War, saying that while he may be in the movie, it is definitely Captain America's story first.

"Ultimately it's Steve's story; it doesn't say ‘Iron Man 4: Civil War'," he says. "I think that's great too. I think Chris [Evans] has been hungry 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. 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."

But why exactly are Stark and Steve Rogers at each other's throats? Plot details aren't for certain yet, but if the film follows the storyline of the comics, all superheroes will required to reveal their true identities and register with the U.S. government. That doesn't sit well with Captain America, whereas Tony Star is one of the initiative's biggest supporters.

Downey Jr. offers some details in the interview that indicate the film's plot might not be too far off. He says asking the question "what would you do" if this happened in the real world is an important thought in moving Tony Stark forward, and that the current political climate makes doing the movie possible in a way that wasn't when the first Iron Man came out.

"There’s always the bigger overarching question, that Joss brings up all the time - it’s kind of weird that these guys would have all these throw downs all over planet Earth and it looked like a little collateral damage happened over there, and yet when the movie's over, it's like nobody minds," he says about the destruction throughout the Marvel films. "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?"

Downey Jr. says fans will see clues as to where Stark's character is headed within Age of Ultron.

Avengers: Age of Ultron hits theaters May 1, 2015. Captain America: Civil War is slated for release May 6, 2016.