Reddit’s Top 10 Avengers Doomsday Theories for 2025, Ranked From Far-Fetched to Frightening

Marvel fans are laser-focused on one thing right now: 'Avengers: Doomsday.' Yeah, 'Spider-Man: Brand New Day' is also on the way, but Doom is the name lighting up group chats. And with that hype comes a flood of theories about how Dr. Victor Von Doom stomps into the MCU and messes with the multiverse. I went through the more interesting Reddit pitches, cleaned them up, and connected the dots where they got tangled. Some of these are clever, some are chaos, a few are deep-lore swings. All of them are very Marvel.

What Reddit thinks 'Avengers: Doomsday' might be

1. Multiple betrayals incoming (and Strange might be one of them)
   The idea here is that Doctor Strange isn’t telling everyone everything. Since the 'one way' speech to Tony during the Thanos fight, this theory says Strange has seen a path where Doom ends up obliterating whole realities to build Battleworld. Expect a painful double-cross somewhere down the line, possibly justified as the only play that keeps any version of reality alive.
2. Earth-616 vs. Earth-10005 sets off a catastrophic incursion
   One thread predicts a collision between the main MCU timeline (Earth-616) and Earth-10005, the designation often tied to Fox’s old Marvel universe. It’s the kind of crossover that breaks everything: per the 'Multiverse of Madness' rules, one timeline has to go. Doom blames the heroes for letting it get this bad, decides Franklin Richards is the key to fixing it, and ultimately lets the multiverse collapse so he can forge something new using Franklin’s powers.
3. Doom hunts the Power Cosmic across universes
   This one has Doom tracking down 'anchor' beings in each reality to steal chunks of the Power Cosmic, all to construct his ideal world and reunite with his wife, Valeria. Meanwhile, Thor supposedly rallies a fresh squad to try and shut this down. If true, expect a cosmic scavenger hunt that gets very personal for Doom.
4. He tries to save the multiverse... until he doesn’t
   Doom senses the rot in the multiverse early and initially plays the savior, pulling heroes together while he stockpiles power. Then the mask slips. The mission to fix everything becomes the excuse to take everything, and the 'rescue' mutates into a straight-up power grab.
5. The Darkhold, the Book of Vishanti, and Loki’s tree are all on the board
   According to this pitch, Doom plane-hops to collect mystical cheat codes: Loki’s Yggdrasil-like multiversal tree, the Darkhold, and the Book of Vishanti. The goal? Reverse the deaths of his parents. But every step the Earth-616 heroes took in earlier phases comes home to roost, and Doom’s attempt to change the past triggers the incursion that spirals toward Doomsday. Yes, the Darkhold was destroyed across the multiverse, but theories gonna theory.
6. Battleworld by design: unleash Franklin at the roots of reality
   A very specific plan: Doom uses Franklin Richards as a living reset switch at Loki’s new Yggdrasil, detonating reality everywhere at once. The kicker is a comics-inspired twist where Doctor Strange sides with Doom and serves as the 'sheriff' of Battleworld. If that title pops up in the movie, expect a lot of knowing nods from longtime readers.
7. Everyone wants Franklin Richards (including Galactus)
   This chain of events starts with Galactus sparing Earth in exchange for Franklin Richards, outing the kid as something way beyond ordinary. Doom goes for the snatch-and-grab on Reed and Sue’s son, forcing the Fantastic Four to teleport out using the device we see in 'The Fantastic Four: First Steps.' They jump to the so-called sacred timeline and land on Earth-616. Supposedly this ties into the 'Thunderbolts*' post-credit scene.
8. Steve Rogers chose family, and Doom hates that
   In the first 'Doomsday' teaser, Steve is holding his baby. That’s a big swing for a guy who has always put duty first. The theory says Doom uses this as a wedge: if Captain America breaks his own code and chooses himself, the whole heroic ideal is compromised. Insiders keep hinting Steve is central to the movie, and the rumor goes further: Doom will make him pay for that choice later in 'Secret Wars.'
9. The Count of Monte Cristo, but make it Tony Stark
   Wild one: in another universe, Tony creates Ultron, gets imprisoned by the Avengers for the fallout, escapes, and returns with a vengeance. It mirrors the Monte Cristo arc: betrayal, confinement, reinvention, revenge. If they actually roll with this, expect an alternate Tony who is not here to quip and make up.
10. That Fantastic Four ship? It’s Doom’s
    The ship slipping into Earth-616 that the Thunderbolts (or New Avengers, depending how the roster shakes out) spot isn’t carrying the Fantastic Four at all. It’s Doom. The heroes race to investigate, get steamrolled and enslaved, and the real FF arrive in a second ship, one step behind. Doom’s endgame: build Battleworld and stuff it with everyone you care about fighting over the same broken sandbox — X-Men, Avengers, Fantastic Four, all of it.

So what’s actually confirmed?

Not much beyond the obvious: Marvel is steering everything toward a multiversal pile-up, Doom is the crown jewel villain fans have been waiting for, and 'Avengers: Doomsday' is officially dated for December 18, 2026. Everything above lives in the theory zone for now — but if even a couple of these ideas land, the movie is going to be a lot.