(Warning: This post contains potential spoilers for Marvel’s Avengers: Doomsday.)
Lewis Pullman‘s Bob Reynolds/Sentry plays a major role in Marvel’s Avengers: Doomsday.
According to insider James Mack, who previously leaked major plot details for Avengers: Doomsday, Pullman’s Sentry is very important to the story.
Sentry’s past—particularly his relationship with his mother, Annie Reynolds—will be explored through emotional flashbacks. He also plays a key role in Doctor Doom’s (Robert Downey Jr.) plan, which becomes central to the film’s main conflict.

According to early story details, Sentry, Doom, and Thor are the most important characters in the Doomsday’s story.
According to the BBC, during production at Windsor Great Park, a second house is being built for Avengers: Doomsday. It is named after Annie Reynolds, Sentry’s mother, and will feature something related to the Void.
In a recent interview with Men’s Health, Pullman opened up about his return as Sentry in Avengers: Doomsday, saying that Bob could be either useful or dangerous to the teams.
Pullman said, “The Thunderbolts don’t want to let him out of their sight because they realize that if he’s caught in the wrong hands, or if he’s not being supported enough by the right people, he might be dangerous. But they also want to keep him close in case they can figure out a way to use him. He’s a very good asset. It’s a hard situation they’re in. With all the other characters that are going to be in Avengers: Doomsday, there will be so many opportunities to figure out how each might come into play—and how Bob might come into play with any of them.”
In Doomsday, Shuri discovers multiversal incursions threatening Earth-616. She warns Sam Wilson, Wong, Banner, and Carol Danvers using a hologram, leading to a larger meeting in Wakanda. Meanwhile, the Fantastic Four arrive, revealing Doctor Doom has kidnapped Franklin Richards and is in a parallel universe, along with Galactus’s involvement.
Shuri detects Monica Rambeau trapped in the colliding universe. Reed confirms Doom and Franklin are there too. A mission forms with three goals: stop the Incursion, rescue Monica, and save Franklin from Doom. America Chavez opens the portal. Sam Wilson leads the Avengers, alongside the Fantastic Four, Thunderbolts, Wakandans, Namor, and others.
The conflict is between Earth-616 and the X-Men’s universe, with a deeper plot involving Doom, the TVA, and Loki. While the main heroes enter the alternate world, others stay behind to defend Earth-616 from an unknown invasion.

Directed by the Russo brothers from a screenplay by their longtime collaborator Stephen McFeely, Avengers: Doomsday is now being co-written by McFeely and Michael Waldron, the creator and head writer of the Loki series. The film features cinematography by Newton Thomas Sigel (Bohemian Rhapsody, X-Men: Days of Future Past) and production design by Kasra Farahani.
In Avengers: Doomsday, the MCU begins the beginning of the end. As the multiverse nears total collapse, the Avengers assemble to face their greatest challenge yet—incursions, catastrophic collisions between realities that could destroy the entire multiverse. Earth’s Mightiest Heroes must race against time to save their reality while confronting the powerful figure behind it all—Victor Von Doom (Downey Jr.).
The official cast members of the film include Downey Jr. as Doctor Doom, Paul Rudd as Ant-Man, Simu Liu as Shang-Chi, Tom Hiddleston as Loki, Florence Pugh as Yelena Belova, Danny Ramirez as Falcon, Sebastian Stan as Bucky Barnes, Winston Duke as M’Baku, Chris Hemsworth as Thor, Letitia Wright as Black Panther, Tenoch Huerta Mejía as Namor, Anthony Mackie as Captain America, David Harbour as Red Guardian, Wyatt Russell as U.S. Agent, and Hannah John-Kamen as Ghost. Ian McKellen as Magneto, Patrick Stewart as Professor X, Rebecca Romijn as Mystique, James Marsden as Cyclops, Kelsey Grammer as Beast, Cumming as Nightcrawler, and Channing Tatum as Gambit. Pedro Pascal as Reed Richards (Mr. Fantastic), Vanessa Kirby as Sue Storm (Invisible Woman), Joseph Quinn as Johnny Storm (Human Torch), Ebon Moss-Bachrach as Ben Grimm (The Thing), and Pullman as Sentry.
Produced by Kevin Feige, Louis D’Esposito, and Russo Brothers will produce through their AGBO banner.
Avengers: Doomsday will be released in theaters and IMAX across the United States on December 18, 2026.