Avengers: Doomsday's First Trailer Sets Up Avengers vs. X-Men In 4 Different Ways

Avengers: Doomsday's recently released trailer sets the stage for some epic Avengers vs. X-Men moments in the MCU. After Disney's purchase of 20th Century Fox went through in 2019, the stage is now finally set for the X-Men to truly be featured alongside Marvel Studios' fan-favorite heroes. 

Marvel Studios released a new trailer for Avengers: Doomsday at CinemaCon 2026, which was not released to the public, ahead of its December 18 debut. The trailer sets up a major battle between the MCU's Avengers and the legacy X-Men from 20th Century Fox's X-Men saga, teasing the impact of the Incursions on the movie's core plot. 

Incursions were first discussed in Doctor Strange in the Multiverse of Madness, when John Krasinski's Reed Richards explained that they happen when two or more universes erode and collide; this eventually leads to one or both worlds being destroyed. Incursions were teased throughout the CinenaCom Doomsday trailer, with multiple characters discussing them and witnessing their effects as the borders between universes start to unravel.

Avengers vs X-Men Battle Teases in Avengers: Doomsday Trailer

Doctor Doom’s Ominous Line

To open this trailer, CinemaCon attendees heard Robert Downey Jr.'s first lines as Doctor Doom, spoken in an unspecified Eastern European (Latverian) accent. He stated that "something's coming" that he and others "may not be able to deter." He concluded by saying that by the time everything is said and done, they will be "faced with an unthinkable decision."

This comes before the first teases about Incursions in the trailer, which will be a major focus for both Doom and the film's multiple teams of heroes. Based on the quote, many believe the decision could be related to stopping an incursion by destroying another universe.

That decision could eventually set the Avengers and X-Men up to battle one another, perhaps fighting for their universe's survival, as Doom muses. While Doom believes he is doing what he needs to do to save humanity, he is sure to put plenty of fear into the hearts of everyone involved in doing so.

Professor X Looking at an Incursion

One shot early in the trailer shows Sir Patrick Stewart in his return to the MCU as Professor Charles Xavier, his second appearance with Marvel Studios after Doctor Strange 2. He is seen looking up at the sky as something approaches the X-Mansion, which some believe is an Incursion.

This shot may show the Incursion in progress, possibly revealing that the world colliding with the X-Men's universe is Earth-616, the main universe from the MCU. That could further indicate that the two superhero teams will be forced to battle one another for the safety of their worlds.

Shang-Chi vs Gambit

Following the opening scenes, the trailer showcases some of the movie's most cinematic moments as the Avengers and X-Men jump into battle. This starts off with two characters who are both making their second appearance in the MCU: Simu Liu's Shang-Chi from Shang-Chi and the Legend of the Ten Rings and Channing Tatum's Gambit from Deadpool & Wolverine.

Shang-Chi uses the Ten Rings to repel a hit from Gambit's staff, which Gambit also used in his Deadpool 3 appearance, sending them flying apart from each other. After Shang-Chi pushes Gambit back, Gambit pulls out a glowing ace of hearts card and shakes his head at the master of martial arts.

Yelena vs Mystique

Another major Avengers vs. X-Men battle comes to light when Florence Pugh's Yelena Belova takes on Rebecca Romijn's Mystique. This will be Pugh's fourth appearance in the MCU as the former Red Room assassin, while Romijn makes her fifth appearance as the shapeshifting Raven Darkhölme and her first since a cameo in 2011's X-Men: First Class.

In the Doomsday trailer, Yelena throws her baton at Mystique before the mutant catches it, donning a white jacket and short, bright red hair that makes her look almost identical to her comic counterpart. After catching the baton, she transforms into a perfect replica of Yelena, and they lock into a chokehold with each other before the shot cuts away.