Avengers: Doomsday Confirmed to Include 2 Pairs of Iconic MCU Siblings

2026’s Avengers: Doomsday will bring a new kind of family feeling with multiple pairs of MCU siblings included in the cast. Along with Robert Downey Jr.’s Doctor Doom, Doomsday’s cast is filled to the brim with MCU veterans and newcomers from multiple universes, giving fans a chance to see a few heroes with ties that go deeper than the field of battle.

Avengers: Doomsday is confirmed to feature two pairs of siblings in its cast, along with multiple characters who have notable siblings in other areas of the MCU. While only 27 members of Avengers: Doomsday's cast are confirmed as of writing, multiple family members will be utilized alongside one another in the MCU's fifth major team-up outing.

Every Pair of Siblings Confirmed & Rumored for Avengers: Doomsday

Sue & Johnny Storm

Arguably the most famous siblings in Marvel history are from Marvel's First Family, the Fantastic Four: Sue and Johnny Storm. This brother/sister pair will make their MCU debut in The Fantastic Four: First Steps, portrayed by Vanessa Kirby and Joseph Quinn upon their arrival under the Marvel Studios umbrella.

This duo will then move to Earth-616 alongside Pedro Pascal's Reed Richards and Ebon Moss-Bachrach's Ben Grimm when they join forces with Earth's Mightiest Heroes for Avengers: Doomsday. Considering their lifelong bond as siblings and the fact that they will have a few years of superhero experience under their belt, this is sure to be a formidable duo as they join the greater universe.

Thor & Loki

Chris Hemsworth and Tom Hiddleston stand as the OG brother combination in the MCU, having played Thor Odinson and Loki Laufeyson since their MCU debuts in 2011's Thor. Including that first movie, they have teamed up in six Marvel Studios movies to date, and they will be back for their seventh run together in Avengers: Doomsday.

Thor is coming off an appearance in Thor: Love and Thunder, which ended with him adopting the young child Love, while Loki now sits as the God of Stories after Loki Season 2 and holds together the timelines of the Multiverse. How they reunite is still largely a mystery, but it is sure to bring plenty of emotion, considering it's been years since they have seen one another alive.

Shuri (T'Challa)

Coming out of the hidden nation of Wakanda is the brother/sister pairing from Black Panther: Letitia Wright's Shuri and the late Chadwick Boseman's T'Challa. The two shared screen time in three movies together (Black Panther and the last two Avengers films) before Boseman's tragic passing in 2020, leading to his character being killed off in the MCU.

Wright is confirmed to reprise her role in Avengers: Doomsday, joining Winston Duke's M'Baku as part of the movie's Wakanda contingent. However, rumors have pointed to Marvel being open to recasting T'Challa as well, possibly lining up a unique sibling reunion should that come to fruition in Phase 6.

Shang-Chi (Xialing)

Shang-Chi and the Legend of the Ten Rings introduced fans to Simu Liu's Xu Shang-Chi and Meng'er Zhang's Xu Xialing, the children of Tony Leung's Mandarin. That film ended with Shang-Chi officially being introduced to the Avengers, while Xialing took on a surprising role as the leader of the Ten Rings organization.

Currently, only Liu is confirmed for the cast of Avengers: Doomsday, bringing Shang-Chi back for his first-ever Avengers film to close out Phase 6. While Xialing is unlikely to join the cast of this major team-up movie, her return is eagerly anticipated as fans wait to see what she makes of her new position in the MCU.

Yelena (Natasha)

Scarlett Johansson is a longtime MCU veteran, having played her iconic role as Natasha Romanoff/Black Widow since 2010's Iron Man 2. She then teamed up with Florence Pugh's Yelena Belova, regarded as her adoptive sister, in 2021's Black Widow, setting the stage for Pugh to take over as the main Black Widow for the MCU moving forward.

Currently, Pugh is in line to reprise her role in Doomsday, leading a group of heroes now known as the New Avengers as she embarks on her biggest adventure to date. Unfortunately, Johansson does not appear to be on her way back as Natasha Romanoff, but fans remain hopeful to see this fan-favorite duo again on the big screen.

BONUS: Nightcrawler (Rogue)

Among the MCU newcomers in Doomsday is Alan Cumming, who became an instant fan favorite by playing Kurt Wagner, better known as Nightcrawler, in 2003's X2. In the comics and other media, he is known to be related biologically to the X-Men's Rogue, both of whose mothers are Raven Darkhölme/Mystique.

While this relationship was never explored in any of the X-Men movies, fans hope to see the X-Men saga's Anna Paquin brought back for Doomsday to play her role as the live-action Rogue. Should she be included alongside Cumming, this movie could finally dive into that dynamic, even if it is just as a nod to fans who know the characters' histories.