Supergirl Just Made Avengers: Doomsday's Job So Much Easier

2026 is proving to be a big year for superhero movies. The DCU's newest installment, Supergirl, has just completed its opening weekend in theaters, helping to define this new era of DC movies, and in just one month, the highly anticipated new Spider-Man movie, Spider-Man: Brand New Day, will be released. The latter movie has already garnered an incredible amount of attention, especially after the Brand New Day trailers revealed a host of shocking plot details—such as, devastatingly, the introduction of MJ's new boyfriend.

Although the wait will be much longer, the first new addition to the Avengers movies in seven years, Avengers: Doomsday, will also hit the big screen on December 18th. That movie, in particular, marks a momentous occasion for the larger Marvel Cinematic Universe. Yes, many MCU movies have been released since Endgame debuted in 2019, but a new Avengers movie in particular is notable and, perhaps even more importantly, an opportunity for the MCU to clearly lay the foundation for where the franchise is going now.

Theoretically, this should have been true with projects after Endgame, but the MCU, for various reasons, has struggled to find a clear, unified, successful path forward. There is therefore plenty of pressure on Doomsday to set the MCU right, and while only time will tell whether the movie does indeed have that long-term effect, help has just come from an unexpected place. Namely, despite the DCU and the MCU being far from allies, one surprising aspect of Supergirl has just offered Doomsday some major help.

Audiences Have Totally Embraced Jason Momoa's Lobo

Supergirl wasn't the on-screen debut of Milly Alcock's Kara Zor-El/Supergirl, as she had appeared briefly at the end of Superman (2025). However, the new flick did introduce several new characters, including Ruthye, the young heroine who ends up becoming a close ally to Supergirl, and Lobo, who sort of becomes an ally to the duo, although that's only true when it suits him. The fickle nature of Lobo is far from the most interesting thing about this character, though. On the contrary, in addition to his bold, chaotic personality and violent nature, the casting of Lobo itself is fascinating.

The DCU, like the MCU, is building its own newfound canon, with, of course, connections to the stories that have decades of history in the larger DC franchise. That's true of Lobo, who has existed as a DC character since the 1980s, when he was introduced in the comics. That also means cutting movies and shows from this new canon, and that has evidently happened with the DCEU's Aquaman movies, considering that the leading actor in those films, Jason Momoa, has stepped out of the role of Aquaman and into that of Lobo.

There were some concerns going into Supergirl that this choice would be distracting for audiences or would otherwise not work because Momoa has already been such a prominent face in other DC stories. Evidently, though, that wasn't the case. In fact, audiences seem to have thoroughly enjoyed Momoa as Lobo, and this history as Aquaman doesn't seem to have impeded that at all. While that's great for Supergirl, inadvertently, it's also very helpful for Doomsday.

Doomsday Will Bring Robert Downey Jr. Back As (Seemingly) Another Character Too

One of the biggest shocks about Doomsday was the revelation that Robert Downey Jr., the beloved actor who has played Tony Stark/Iron Man since the MCU began and then tragically met his end in Endgame, would be returning to the franchise, this time as Doctor Doom himself. When this reveal happened, it immediately sparked fan theories and speculation regarding how this could possibly be. The most prominent theory even now is that Doctor Doom is going to be revealed as a Tony Stark variant, which would be one great way—but certainly not the only way—to explain it.

One thing that did feel certain right away was that the MCU would not simply be bringing RDJ back as a totally new character without addressing or explaining it in some way, as that would have been too absurd. Hilariously, Supergirl just proved that's apparently not too absurd, as DCU fans accepted the return of Momoa as an entirely different character, but this is still a very different situation. Aquaman was an important character, but Tony Stark was at the very core of the MCU; it wouldn't make sense at all to follow this approach with Downey Jr.'s return.

Even so, Supergirl has set Doomsday up for success by already providing superhero fans with an example of a major franchise actor coming back as a new character and doing a solid job. In fact, although these are two separate franchises, it will make it harder for naysayers to criticize Doomsday for this choice, given how warm a reception Momoa received for his role as Lobo in Supergirl.

• 

  Supergirl

  

  6/10

  Release Date June 26, 2026

  Runtime 108 minutes

• 

  Avengers: Doomsday

  Release Date December 18, 2026

  • 
  • 

    Vanessa Kirby

    Sue Storm / Invisible Woman

  • 

    Johnny Storm / Human Torch

  • 

    Ebon Moss-Bachrach

    Ben Grimm / The Thing