This DC Comics theory has me convinced that Supergirl will appear as a villain in Superman

Just like many, I am also really excited about Superman, which will kickstart James Gunn's ambitious DC Universe. Warner Bros. Pictures will release the film on July 11, 2025. Here's the official synopsis:

"Superman, a cub reporter in Metropolis, embarks on a journey to reconcile his Kryptonian heritage with his human upbringing as Clark Kent."

There is a DC theory that's floating around the internet that has made me think Supergirl might actually have a role in this film. That too of a villain. It might sound bizarre. Let us look into that theory and what I'm trying to suggest here.

Superman might feature Supergirl as the villain

So here me out, there is a theory on the internet that suggests that Milly Alcock's Supergirl will be the villain in the upcoming Superman film. Its hint is in the official trailer where we might have seen her glimpse. The film will feature several superheroes, including Mister Terrific, Hawkgirl, Guy Gardner, and Metamorpho.

There is also a host of villains like Ultraman, Lex Luthor, and the Kaiju, among others. The Hammer of Boravia also features in the James Gunn-directed film, which is an armored and masked entity that has a lot of strength as well as heat vision. In the trailer, we are not able to see its identity because of the helmet. I feel its abilities are similar to Superman's, which is where this theory comes into play.

It's possible in a Gunn universe that Kara Zor-El/Supergirl might be the real Hammer of Boravia. The Boravia has four superpowers that are similar to Supergirl's. There are also theories that she was created by Lex Luthor.

Alcock's film, Supergirl: Woman of Tomorrow, is slated to be released on June 26, 2026. Given that the film's release is a year away from now, the makers might introduce her as the antagonist in Superman, and that would increase the hype around her film.

Superman, meanwhile, is written and directed by James Gunn. The film is the first in the DC Universe, which will consist of several films and shows that DC will be releasing over the next years. David Corenswet has replaced Henry Cavill as the titular superhero.

In an interview with IGN, Gunn spoke about the casting of Corenswet and said,

“I've always believed that the casting is the most important and that as long as the actor is the best possible actor for that role, that's more important than it is for a name."

He continued,

"Especially in today's market, which is you see movie stars are not the same as they used to be in terms of you can't, like what it was 15 years ago, open up a Melissa McCarthy movie. Instantly, you're going to make this much money. Open up an Adam Sandler movie, instantly you're going to make this much money. It's not like that anymore. So I just wanted to go for who was the best Superman.”

Superman will be released on July 11, 2025, by Warner Bros. Pictures. Only then will we realize if this theory of mine holds any water or not. In case it turns out to be true, it will automatically increase the stakes and will generate more excitement about Supergirl.