Can Avengers: Doomsday Live Up to Endgame? Robert Downey Jr. Says Yes — Here’s Why Fans Are Worried

Robert Downey Jr. wants you to know that he gets it. The pressure. The expectations. The impossible task of following up Avengers: Endgame, a movie that earned $2.8 billion and made grown adults weep in packed theaters around the world. The man who launched the Marvel Cinematic Universe as Tony Stark in 2008 and said goodbye to the character in 2019 is now returning — not as Iron Man, but as Victor von Doom, the villainous ruler of Latveria. And he’s acutely aware of the stakes.

“We’ve labored long and hard to make sure this will not be a letdown after Infinity War and Endgame,” Downey said in a recent interview that quickly made the rounds across entertainment media. The quote landed with the weight you’d expect from someone who knows the MCU’s post-Endgame era has been uneven, to put it kindly. Audiences are eager but skeptical. The goodwill is there, but it’s not infinite.

Avengers: Doomsday, directed by Joe and Anthony Russo and scheduled for December 18, 2026, is shaping up to be the most consequential Marvel movie since Endgame. It brings Downey back to the franchise as an entirely different character, unites a sprawling cast that includes Florence Pugh, Pedro Pascal, Anthony Mackie, and virtually every major MCU hero still standing, and attempts to make Doctor Doom the universe-level threat that Thanos was — without simply repeating the same playbook.

RDJ as Doom: Genius Move or Desperation Play?

When Marvel announced at San Diego Comic-Con 2024 that Downey would return as Doctor Doom, the reaction was electric — and divided. On one hand, the symmetry is undeniable. The actor who built the MCU now threatens to tear it down. The face that defined heroism for a generation of moviegoers is now hidden behind a metal mask. It’s the kind of bold, metatextual swing that only Marvel could even attempt.

On the other hand, casting Downey as Doom raises uncomfortable questions. Is this creative audacity, or a safety net? After a string of post-Endgame projects that underperformed — The Marvels, Ant-Man and the Wasp: Quantumania, and Secret Invasion all struggled critically or commercially — bringing back the franchise’s most bankable star as a villain reads, to some, less like inspiration and more like a Hail Mary.

The Russos have addressed this tension directly. At SXSW London earlier this month, Joe Russo described their approach: “It’s that sweet spot between being very specific and unique to the original story that happens within this film but also delivering on what the most awesome things are about Doom in the comics.”

He added: “We always look at it as our job to not tell you a story that you’ve heard before. We’re never translating directly from the comics. The Doom in Doomsday will be what we love most about the comics and also what is original to our storytelling, what is brand new.”

That word — “original” — is doing a lot of heavy lifting here. And it’s exactly what has some fans worried.

The Doctor Doom Problem

Comic book fans have been burned by Doctor Doom adaptations before, and the scars run deep. Julian McMahon’s 2005 version in Fox’s Fantastic Four turned one of Marvel’s most operatic villains into a petulant CEO who gets hit by lightning. Toby Kebbell’s 2015 take was a moody hacker with a green hoodie. Neither captured the character’s defining quality: his grandiose, theatrical, “being a god is beneath me” energy.

A proper Doctor Doom — the one that has made him the greatest villain in Marvel Comics for six decades — is a walking contradiction. He’s a scientist and a sorcerer. A tyrant beloved by his people. A man whose vanity and genius are so intertwined that he hides his face behind an iron mask because of a tiny scar, convinced that even the slightest imperfection is unacceptable. He speaks in the third person. He sends the Fantastic Four back in time to fight pirates not because it serves a strategic objective, but because Doom does not think small.

The Russos’ emphasis on “original storytelling” raises the question: will this Doom be recognizable as the character fans have loved for decades? Or will he be another reinterpretation that sands off the weirdness, the grandeur, the sheer comic-book absurdity that makes him compelling?

There’s at least one encouraging sign: the costume. Early looks at Downey in the Doom armor reveal a comic-accurate design — the armored body, the green tunic, the hood. It’s a visual statement that suggests, at minimum, the creative team isn’t embarrassed by the source material. But a good costume isn’t a good character, and fans who lived through the Fox era know the difference.

The Fantastic Four Problem

Perhaps the biggest red flag for Doom purists is the apparent lack of connection between Doctor Doom and the Fantastic Four. In the comics, Doom’s entire identity is shaped by his relationship with Reed Richards — his college roommate, his intellectual rival, the man he blames for the accident that scarred his face. Their dynamic is the spine of Marvel’s First Family, and Doom without Richards is like Joker without Batman: technically possible, but missing the point.

The MCU’s Fantastic Four: First Steps introduced Reed Richards (played by Pedro Pascal) in 2025, but outside of a post-credits tease and an empty Latverian seat at the United Nations, there’s been no indication that the Doom-Richards rivalry will be central to Doomsday. If the Russos are building a Doom who stands apart from the Fantastic Four mythology, they’re gambling that audiences will embrace a version of the character that deviates significantly from the comics.

That could work. It could also be the exact kind of “original” approach that left earlier adaptations in the dust.

What We Know About the Plot

Marvel is keeping details tight, but the broad strokes are emerging. Doctor Doom emerges as a multiversal threat following the collapse of the Sacred Timeline — a direct consequence of the events in Loki season 2 and Doctor Strange in the Multiverse of Madness. The Avengers, now a fractured and reassembled team led by Sam Wilson’s Captain America and including the new Fantastic Four, must confront a villain who doesn’t just want to conquer the world — he wants to remake reality itself.

The cast is enormous, and that’s both a feature and a potential bug. The Russos have proven they can juggle massive ensembles — Infinity War and Endgame gave meaningful moments to dozens of characters. But the MCU has only gotten bigger since then, and the risk of characters feeling like glorified cameos is real.

Spider-Man: Brand New Day — The Other 2026 MCU Gamble

While Doomsday dominates the conversation, it’s not the only Marvel movie making waves this summer. Spider-Man: Brand New Day, Tom Holland’s fourth solo outing as Peter Parker, hits theaters July 31, 2026 — and it’s shaping up to be one of the most interesting MCU entries in years.

Set four years after No Way Home, the film finds Peter living alone in a New York that has forgotten his identity, fully committed to being Spider-Man. But the movie’s most intriguing element is its connection to the Netflix Defenders universe. Jon Bernthal returns as the Punisher, Michael Mando appears as Mac Gargan (Scorpion), and Tramell Tillman joins the cast in an undisclosed role. It’s the first time the MCU has explicitly folded the Netflix-era characters into a flagship film, and it signals that Marvel is finally weaving those threads back into the main tapestry.

The film is directed by Destin Daniel Cretton (Shang-Chi), with Sadie Sink joining the cast in what’s rumored to be a major role. The trailer, released in March, has already racked up over 3.5 million views, and early tracking suggests another billion-dollar Spider-Man movie is all but guaranteed.

The Stakes for Marvel in 2026

Looking at the calendar, 2026 is a make-or-break year for the MCU. Avengers: Doomsday in December and Spider-Man: Brand New Day in July are the two tentpoles. Between them, they need to accomplish what the post-Endgame slate hasn’t: restore the sense that the MCU is building toward something essential, not just producing content to fill a release schedule.

Robert Downey Jr.’s return is the clearest signal yet that Marvel understands the stakes. They’re not trotting him out for a cameo or a flashback — they’re handing him the franchise’s most iconic villain and asking him to make audiences feel the way they felt when Thanos snapped his fingers.

Whether that’s a brilliant reinvention or a desperate swing will be decided when Doomsday arrives this December. For now, the only certainty is that the man in the iron mask has everyone’s attention.