Marvel unveils Avengers: Doomsday trailer, Doctor Doom attacks at Comic-Con

Marvel’s Avengers: Doomsday footage turned San Diego Comic-Con’s Hall H into a Doctor Doom showcase, with Sentinels pointed at the Avengers, Fantastic Four and X-Men. The Hall H sneak peek also put Reed Richards face to face with Doom, making the movie look less like a single sequel than the opening move in Marvel’s attempt to stitch its biggest franchises into one event story.

That framing mattered because Marvel had stayed out of Hall H in 2025. After that absence clouded the convention for many fans, Marvel returned in 2026 with a planned run from Thursday, July 23 through Sunday, July 26 and a larger show-floor presence. The studio had already used Comic-Con to elevate the Fantastic Four in 2025, with immersive booths at #2329 and #2519, a sign that Marvel’s first family was being positioned as a central pillar of the company’s convention branding.

Marvel set up the film months earlier. On March 26, 2025, the studio announced that production had begun on Avengers: Doomsday and that it would reach theaters on May 1, 2026. Disney’s livestream reveal named Chris Hemsworth, Vanessa Kirby, Anthony Mackie and Sebastian Stan among the cast, giving the project the kind of marquee lineup that can anchor a crossover built to pull together multiple corners of the Marvel universe.

The Doctor Doom material also fit Marvel’s comics strategy. The company’s One World Under Doom tie-in line said Doom’s dominion over the Marvel Universe begins in February, with tie-in issues in Fantastic Four #19, Storm #5 and X-Factor #7. Marvel has also used Doom Sentinels in X-Men and Fantastic Four comics before, so the robot army in the Hall H footage carried a comics precedent rather than functioning as a one-off visual gag.

Reaction to the trailer centered not only on Doom’s attack but on the characters left out of the footage. A July 20 Reactor analysis focused on the major names missing from the trailer, underscoring how roster omissions became part of the story alongside the reveals themselves. For Marvel, the combination of Doom, Sentinels, Reed Richards and Hall H is now doing the work of a reset: one villain, one image and one crossover narrative meant to pull a fatigued audience back into a single shared event.