Robert Downey Jr. Making 'Iron Man 4'? Highest Paid Actor Teases Marvel Sequel

Without a shred of a doubt, there would be no Marvel Cinematic Universe without Robert Downey Jr., whose superhero Tony Stark won the hearts of millions all over the world when kick-starting the franchise way back in 2008. After three stand-alone movies and multiple appearances in the character (most recently in Captain America: Civil War), could he go back for Iron Man 4?

Days after Marvel confirmed Downey would be joining the cast of the studio's co-production with Sony Pictures, Spider-Man: Homecoming, Downey is still doing press rounds for his appearance in Civil War, and he seems just as willing to go back to work on Stark Tower as he did back in 2008.

"I feel like I could do one more," Downey said on ABC's Nightline earlier this week, when asked whether he'd be up for another Iron Man stand-alone movie. "[Tony Stark] always danced to the beat of his own drum [and he's] feeling a little bit of guilt of the actions the Avengers have taken, and the collateral damage we have caused, where he feels responsible."

There's also the fact that he's made a ton of money for playing arguably the most iconic of all Avengers. For the past three years, Downey has been named the highest-paid actor in the world by Forbes, and on 2015 alone he made $80 million between his actual salary and his share on the MCU's films success at the box office.

Downey has appeared on three Iron Man films, had a starring role on the two Avengers movies released so far and also plays a pivotal role in this year's Civil War, a sort of proto-Avengers movie where all the main MCU superheroes but The Hulk and Thor are around to battle each other, in a film that already holds an impressive 94 percent on critics aggregator website Rotten Tomatoes.

So far, Downey has been confirmed in three upcoming MCU films: Spider-Man: Homecoming and the two Avengers: Infinity War movies.

Civil War hits theaters in the U.S. next Friday.