Note: This post contains potential spoilers for Avengers: Doomsday and Secret Wars.
Some concept art for Avengers: Doomsday and Secret Wars was previously leaked. It was posted on ArtStation by one of Marvel’s former concept artists, but the images were later removed.
According to a new report from insider James Mack on X, who previously leaked important plot details for Avengers: Doomsday, he claims to have seen some sketches for Avengers: Secret Wars.
The film’s aesthetic reportedly adopts an ancient, medieval style reminiscent of the 1602 universe from What If…?. Some art shows a kingdom on Battleworld, where Doom resides, featuring castles and a mythical vibe. Earlier leaks had hinted at this.

So, the leaked concept art appears to have a connection to Avengers: Secret Wars. It seems Robert Downey Jr.‘s Doctor Doom will be creating Battleworld at the end of Doomsday or time-traveling into medieval times.
Avengers: Doomsday filming is currently underway in the United Kingdom. We recently received plot details for Avengers: Doomsday, revealing that an Incursion occurs as Earth-616 and Earth-10005 begin colliding. To stop the Incursion and save Earth-616, a three-part mission is formed. Wong calls on America Chavez to open a portal.

Directed by Russo brothers from a screenplay by their longtime collaborator, McFeely. Newton Thomas Sigel (Bohemian Rhapsody, X-Men: Days of Future Past) will be the cinematographer.
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 Lewis 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, and Avengers: Secret Wars is scheduled for release on December 17, 2027.
Source: James Mack/X