A fresh wave of theories has exploded online following Marvel’s recent livestream — the one that bizarrely centered on furniture but stealthily dropped major casting bombs for Avengers: Doomsday. Among the wildest and most intriguing speculations? A theory suggesting Robert Downey Jr.’s Doctor Doom may owe his origin to the events of X-Men: Days of Future Past.
While fans continue to dissect the trailer frame by frame and read into everything from character positioning to costume colors, one particular theory from Screen Rant’s Liam T. Crowley has caught fire on social media. According to Crowley, the return of several legacy X-Men actors — including Kelsey Grammer, Patrick Stewart, Ian McKellen, James Marsden, and Alan Cumming — might be more than just nostalgic fan service. Instead, their presence could be a direct result of the time-twisting finale of Days of Future Past.
Let’s rewind. In the 2014 film, Wolverine was sent back in time to prevent a dystopian future ruled by Sentinels. The mission succeeds, the timeline is reset, and a brighter, more hopeful reality emerges. Mutants who had perished were alive once more, and all seemed well.
But what if that reset had unintended consequences?
Crowley floats the idea that undoing the original dark timeline may have inadvertently fractured reality, creating ripple effects that gave rise to an alternate version of Tony Stark — one who, instead of becoming Iron Man, evolved into the MCU’s incarnation of Doctor Doom. It’s a compelling possibility, especially when paired with Tony’s own warning from Avengers: Endgame: “When you mess with time, it tends to mess back.”
Could the “messing back” be the emergence of a multiversal tyrant in familiar armor?
If true, this would be a brilliant way for Marvel to bridge the once-separate Fox X-Men universe with the Marvel Cinematic Universe, allowing characters and timelines to collide in organic, story-driven ways. It also cleverly places the roots of Avengers: Doomsday in a film that predates most multiverse talk in the MCU — suggesting that the seeds of this epic crossover were planted long ago.
Of course, there’s another layer to consider: variants. With Deadpool & Wolverine poised to feature an alternate Logan and previous films already introducing variant versions of classic heroes (RIP multiverse Charles Xavier in Doctor Strange in the Multiverse of Madness), these returning X-Men actors might not be reprising their original roles, but rather portraying new takes on familiar characters. Perhaps even versions aligned with the upcoming animated X-Men ’97.
As with all Marvel theories, only time — and the next trailer — will tell. Until then, fans will continue connecting dots, deciphering hints, and debating timelines. One thing’s certain: when Avengers: Doomsday hits theaters on May 1, 2026, the multiverse may never be the same.
