Avengers: Doomsday theories have taken over fan forums since Marvel confirmed Robert Downey Jr. as Doctor Doom. That casting pulled one of the franchise’s most loved actors back into the story as its most feared villain. The villain now sits at the centre of a film that draws the Avengers into the orbit of the X-Men. The strongest theories are the ones that hold up against everything Marvel has shown so far.
This guide works through the big questions around Doom and Steve Rogers before turning to the mystery of the Latverian Witch. It closes with the practical details you need before opening night.
What Should I Know About Doctor Doom?
Doom Is a Version of Tony Stark
The most popular theory starts with the face Doom shares with Tony Stark. Tony’s face could belong to a variant from another universe who took a darker path. A stranger version has Doom using science and sorcery to take over Tony’s body after Endgame. The comic Iron Man: Legacy of Doom inspires another reading where Downey plays both characters. Each version leaves heroes like Spider-Man facing the face of their fallen mentor.
Doom Is the Real Protagonist
A quieter theory casts Doom in the role Thanos played in Avengers: Infinity War. Thanos drove that story with a goal the audience could follow and the Avengers spent the film reacting to him. Doom could hold the same position with logic that is even harder to argue against. Fans on the MCU theory boards have made this case for months. The reading gives Downey a villain with real weight.
What Happened to Steve Rogers?
Steve Stayed in the Past With Peggy
Chris Evans returns as Steve Rogers and the first teaser shows him holding a newborn baby. The baby connects to the final moments of Endgame when Steve chose a life with Peggy Carter. That choice may have created the timeline where the Fantastic Four live. The timeline would then explain how Steve and the Fantastic Four cross into the main MCU together. Hayley Atwell’s return as Peggy at San Diego Comic-Con has given the theory fresh momentum.
The Steve in the Trailer Is Loki
The full trailer shows Thor stunned to see his old friend again. That reunion ends with Mjolnir flying into Steve’s hands. Loki can shapeshift and could wear Steve’s face to win Thor’s trust against Doom. A darker comic-book reading points to Captain Hydra as an altered Steve who serves the enemy. Marvel has edited trailers to hide twists before so the scene may show less than it seems.
Who Is the Latverian Witch?
Wanda Maximoff
Marvel revealed a costume labelled the Latverian Witch at San Diego Comic-Con in July. Elizabeth Olsen’s Scarlet Witch became the leading suspect within minutes. Wanda shares a long history with Doom through the comic storyline The Children’s Crusade. A mask would also let the production use a body double for Olsen when needed.
Cynthia von Doom
Doom’s mother is a sorceress in the comics and her pact with Mephisto shapes Victor’s relationship with magic. That relationship would explain the witch’s tie to Latveria in the simplest terms. Cynthia would also give this Doom an origin rooted in grief. No official source has linked her to the film so far.
A Coven of Heralds
The witch costume changed colour over the course of the convention. Each colour change pointed to a group of witches in Doom’s service. Some fans link the colours to the magic system from Agatha All Along. That coven could act as heralds who carry Doom’s influence across the multiverse.
Peggy Carter in Disguise
One witch theory loops back to Steve Rogers. A Latverian Witch could take Peggy’s likeness to manipulate Steve at a crucial moment. That moment would strike Steve where he is most vulnerable. Marvel revealed the witch and Atwell’s casting in the same Comic-Con weekend.
How Will Doomsday Set Up Secret Wars?
Franklin Richards Holds the Key
Doomsday leads into Avengers: Secret Wars and both films draw on the 2015 comic by Jonathan Hickman and Esad Ribić. The comic makes Franklin Richards one of the most powerful beings in the multiverse. Franklin is the son of Reed Richards and Sue Storm and can create whole universes. Fans believe Doom wants that power to build Battleworld from the wreckage of the multiverse.
A Universe Will Be Destroyed
The bleakest theory expects an incursion to wipe out an entire universe on screen. Incursions happen when two universes collide and one must end so the other survives. Marvel has teased the threat since Doctor Strange in the Multiverse of Madness. Many fans expect the heroes to lose the final battle and leave Secret Wars to rebuild what remains.
Which Avengers: Doomsday Theories Should I Believe?
The Steve Rogers theories rest on the firmest ground. Marvel has built his return around Peggy and the teaser leans hard on his life in the past. His past almost certainly shapes the wider story.
The Stark connection remains the biggest open question. Marvel cast Downey for a reason and audiences will expect an answer that justifies his return. The witch theories are harder to call because a masked costume leaves room for many readings.
December will settle most of these debates. Until then the trailers reward a second viewing. Keep your favourite theory ready for opening night.
What Else Should I Know Before Avengers: Doomsday Comes Out?
When Is Avengers: Doomsday Out?
Avengers: Doomsday opens in US cinemas on 18 December 2026. Marvel moved the release from its original May slot to give the production more time. Release dates can shift by a day or two in other markets so check your local cinema listings.
Who Is in the Cast?
Robert Downey Jr. leads the cast as Doctor Doom. Chris Hemsworth returns as Thor alongside Tom Hiddleston as Loki. Pedro Pascal and Vanessa Kirby bring the Fantastic Four into the story. Patrick Stewart and Ian McKellen return from the original X-Men films with Channing Tatum as Gambit. Florence Pugh and David Harbour carry over from Thunderbolts*.
Who Is Directing Avengers: Doomsday?
Joe and Anthony Russo direct the film. The brothers also directed Avengers: Infinity War and Avengers: Endgame. They announced Downey’s casting at San Diego Comic-Con in 2024. Filming took place in the UK.
Is There a Trailer?
Marvel released a teaser in December 2025 that confirmed Steve Rogers would return. The full trailer followed in July 2026 just ahead of San Diego Comic-Con. Both trailers have fuelled most of the theories above.
What Comes After Avengers: Doomsday?
Avengers: Secret Wars follows on 17 December 2027 in the US. That film concludes the Multiverse Saga and brings Downey back as Doom. Doomsday sets up the stakes for the finale.