Robert Downey Jr. is reportedly set to sign on to Captain America 3, which may bring fans the Civil War storyline from Marvel’s comic books and start a new phase of movies for the studio.

Variety has just reported that Iron Man actor Robert Downey Jr. will be joining the highly anticipated Captain America 3 with actor Chris Evans. The actor is in final negotiations to play Tony Stark once again in the third Captain America, which is set to hit theaters May 6, 2016.

While Robert Downey Jr. has been hinting (and then denying) rumors that Iron Man 4 is being written, it seems that one of those other films he was hinting at may have him joining up with Captain America.

Marvel plan to pit Tony Stark against Steve Rogers as they battle over the Superhero Registration Act, which would force anyone with superhuman abilities to identify themselves to the U.S. government. It also makes them agree to being involved in local police forces.

In the comics, Iron Man supports the program, while Captain America is against it due to it causing some issues with civil liberties. This causes a fallout between the two superheroes, which we saw hints of in The Avengers, and causes Rogers to leave society to avoid being put into custody.

Apparently Marvel intended to hire Robert Downey Jr. for a smaller role in the film, which would reportedly only have taken three weeks to film. Now it seems he will have a much larger role, which could mean he’s somewhat of a villain in the film in Rogers’ eyes.

Downey reportedly wanted Stark to have a larger role in the film, which supposedly angered Marvel Entertainment chief Ike Perlmutter. Perlmutter ordered the film’s screenwriters to write Iron Man out of the Captain America 3 script, according to Variety’s sources.

After the deal fell through, Marvel’s president Kevin Feige worked with Downey in an attempt to continue and solidify his role in the MCU. Downey will reportedly earn $40 million for his part in the film, not including the backend profits.

He will also get an additional payment if Captain America 3 outperforms The Winter Soldier, which wowed the studio with its $714 million at the worldwide box office. This is very likely to happen now that Iron Man will be joining Captain America in the third film.

So far there are no official comments from Marvel or Robert Downey Jr., but clearly there are some solid details here, and we look forward to seeing the two superheroes together in the Captain America threequel.

It should be noted that Captain America 3 is set to be released the same year that Batman v Superman: Dawn of Justice will hit theaters. Could we have two superhero duos battling each other in the same year? More importantly, will it be called Iron Man v Captain America: Civil War? We hope so.

Robert Downey Jr. and Chris Evans will be seen next in The Avengers: Age of Ultron on May 1, 2015, and if all goes well we’ll be seeing them in Captain America 3 on May 6, 2016.