Warning: Contains SPOILERS for Shang-Chi and the Legend of the Ten Rings.
Multiple Avengers cameo in Shang-Chi and the Legend of the Ten Rings, but Bruce Banner’s look is completely different from Avengers: Endgame‘s Smart Hulk. The second film in Phase 4 of the Marvel Cinematic Universe mostly stands on its own. It focuses on the origin of Shang-Chi (Simu Liu) and his battle against his father. Shang-Chi‘s ending sets up his future in a surprising way by introducing the Master of Kung Fu to members of the Avengers.
Shang-Chi includes various MCU cameos throughout the main runtime, and in almost every instance, the look of the characters changes in some way from their past look. Abomination was completely redesigned from The Incredible Hulk, while Wong and Trevor Slattery even had differences. But, the movie packed in a few more surprising cameos thanks to the post-credits. Shang-Chi‘s end-credits scenes featured Captain Marvel (Brie Larson) and Bruce Banner (Mark Ruffalo). While Carol Danvers’ hair is long again after Avengers: Endgame, it is the form that Bruce appears in that will be the biggest shock to viewers.
After transforming into Smart Hulk in Avengers: Endgame, Bruce’s normal human form is featured in Shang-Chi‘s post-credits. This confirms that he has reversed his Smart Hulk transformation after just one film, but Shang-Chi doesn’t have the time to explain why this happened. It’s a major looming question for the MCU to deal with in Phase 4, and the likely answer could lie with the upcoming Disney+ show She-Hulk. The series stars Tatiana Maslany as Jennifer Walters, Bruce’s cousin in the comics who becomes She-Hulk after a blood transfusion with Bruce. It is possible that Bruce already did this between Avengers: Endgame and Shang-Chi, and the transfer of his blood and gamma radiation means he no longer could be Smart Hulk.
There are other possible explanations for why Smart Hulk would transform back into Bruce Banner. Even if he could still be in his Hulk form, Bruce may have decided to leave that part of him behind if She-Hulk exists at this point in the timeline. This would allow Bruce to retire from his days as a superhero but still help the Avengers as a consultant, which seems to be the role he’s serving in Shang-Chi‘s post-credits. The comics present other possible solutions too, such as a mental failsafe that prevents Hulk from taking too much control or someone finding a cure for Bruce’s gamma radiation. Either of these could be other solutions to why Bruce Banner returned already.
Since Shang-Chi and the Legend of the Ten Rings only presents Bruce Banner after reversing his Smart Hulk transformation, the real answer for what happened to him is sure to come in She-Hulk. Whether it is tied to She-Hulk’s origin or something else, Hulk’s role in the show is confirmed. There is even evidence to suggest that Ruffalo did more motion-capture work to bring a version of Hulk to life, so the series could be where the MCU shows how Smart Hulk became Bruce Banner again. This is a good sign that She-Hulk will be where MCU fans learn exactly how or why Bruce’s Smart Hulk form is no more.