CinemaBlend participates in affiliate programs with various companies. We may earn a commission when you click on or make purchases via links.

Actors like Robert Downey Jr. have left such an indelible impression with roles like Tony Stark in Iron Man that it feels like no one else could play them. On the surface, most could agree with that sentiment, seeing as it went so well there was never a doubt cast on Downey’s casting, leaving him to play the role for a little over a decade. Even The Suicide Squad and Guardians of the Galaxy helmer James Gunn made a great point in that debate, proving that while there’s always a tantalizing “what if” scenario or two, not just anyone makes an impression like Downey did with that pivotal role.

Responding to a claim by The Sunday Times that Iron Man basically could have worked with "almost anyone with wit" thanks to an alleged loyalty to character over actor, Gunn took to Twitter to rebut that statement. And in true form, his case against was a simple but effective takedown that came with all of the proof that any one could need to agree. Here’s how James Gunn debunked that claim, and the proof he cited to do so:

“I’ve seen the screen tests” is one of those statements that cuts pretty deep, especially when coming from someone who’s had pretty extensive access to the MCU like James Gunn has. Whether he means that he only saw the screen tests showing Robert Downey Jr. originally tackle Tony Stark as a more brooding character, or the tests of other actors for the role, is undetermined. But in either scenario, the point stands that audiences aren't just attached to Iron Man's lead character because he's a Marvel star. Without Downey's performance landing how it did, at the exact moment that it did, we may not have had an MCU to speak of.

Robert Downey Jr sits on the couch testing a Repulsor glove in Iron Man.

Looking at Downey’s tests alone, Iron Man clearly would not have worked like it did with a more Batman Begins style performance. Sticking to a firm and melancholy Tony, Robert Downey Jr. could have found himself unfairly compared to Christian Bale; which only would have hurt in the same summer that The Dark Knight unleashed its own grim superhero tale. But through the improv heavy production allowing Downey's own charm to infuse itself into Jon Favreau's film, Tony Stark became the man we all saw on the screen in the summer of 2008. And it was a sharp contrast to Bruce Wayne, allowing both billionaire playboy genius philanthropists to coexist at the box office, rather than the proven brand taking a decisive lead.

As much as Robert Downey Jr.’s Iron Man has landed as the definitive cinematic version of the Marvel hero, it’s hard to forget that Tom Cruise was also suggested for the lead. Thinking about how Cruise’s own mix of devil may care comedy and serious action chops could have kicked off the Marvel Cinematic Universe, you could see an equally iconic version in that thought experiment. But again, Cruise Iron Man wouldn't have given Tony Stark the same sort of pathos and charm that Robert Downey Jr.'s variant did. Which just circles us back to James Gunn's overall point that it's not the character of Tony Stark, but rather Downey's version of the character, that audiences fell in love with.

Robert Downey Jr. is the Iron Man of our universe, and much like James Gunn is ready to redefine what the world should expect from The Suicide Squad, that wasn't just because of the franchise name on the door. Gunn’s big and bold sequel opens in theaters this weekend, while the legacy of Downey’s Tony Stark can be found in its entirety on Disney+. If you’re not a subscriber yet, and want to take that walk down memory lane, check out the Disney Bundle offer, which also includes ESPN+ and Hulu, in one convenient subscription.

Up Next

James Gunn Has A Bunch To Celebrate As The Suicide Squad's US Premiere Coincides With GOTG's Anniversary

How Marvel Hilariously Threw Shade At Old Captain Marvel Criticisms news 3h How Marvel Hilariously Threw Shade At Old Captain Marvel Criticisms Corey Chichizola
One Marvel Director Seemingly Wants The Snyder Cut Treatment For His MCU Blockbuster news 6h One Marvel Director Seemingly Wants The Snyder Cut Treatment For His MCU Blockbuster Adreon Patterson
7 Marvel Characters That Jason Alexander Would Be Perfect To Play news 20h 7 Marvel Characters That Jason Alexander Would Be Perfect To Play Jason Wiese