Fantastic Four star says Robert Downey Jr. is doing the "most amazing work" as Doctor Doom in Avengers: Doomsday

There are a lot of reasons to be skeptical about Robert Downey Jr.'s impending portrayal of Doctor Doom in the Marvel Cinematic Universe. But according to Fantastic Four: First Steps actor Vanessa Kirby, who portrays Sue Storm in the film, the MCU veteran is more than living up to the potential of his new role as the Avengers' next great nemesis.

"Oh, beyond. Beyond," Kirby tells the HappySadConfused podcast when asked about how she's getting along with RDJ as they both film the currently in production Avengers: Doomsday. "He's the most incredible human being. Soulful, deep, kind. He's been an amazing leader to us, considering we're the newbies. A lot of the others have known this world for a really long time. He's been a phenomenal leader, and he's also just doing the most amazing work."

It's expected that Kirby is working closely with Downey, considering the history between Doom and the Fantastic Four. I've been a little bit on the fence about Downey's casting, as Doctor Doom is my favorite character, and I'm a little worried there will be some kind of Tony Stark twist on the MCU version of the villain.

That said, so far, all signs have pointed to a version of Doom that at least looks like Jack Kirby's classic comic book design, which has never been fully embodied in any of the officially released Fantastic Four films so far. And that's certainly one of the biggest points in making sure that Robert Downey, Jr. manages to pull off a perfect performance as Doctor Doom across Avengers: Doomsday and its sequel, Avengers: Secret Wars.

The Fantastic Four: First Steps hits theaters on July 25 to kick off Marvel Phase 6. For more, check out our guides to upcoming Marvel movies and shows and how to watch the Marvel movies in order.