Man of Steel may not have gotten the unanimous critical reception Warner Bros. hoped for when the film arrived in theaters in 2013, but that didn't really matter. The film successfully jump-started the DC Extended Universe of movies, and many fans out there didn't care what critics had to say about Superman's triumphant return to the big screen. This was a movie that finally allowed Superman to throw an actual punch, to cut loose, and be accurately portrayed in all his Kryptonian glory on the silver screen.
Still, thanks to the generally lukewarm reception to the film, plans for a Man of Steel sequel were put on hold. Instead of focusing its attention on making a Superman sequel, Warner Bros. set its sights on the second chapter in the infant universe, plans which included expanding the DCEU dramatically.
By introducing Batman and Wonder Woman, the DCEU got a lot bigger very, very fast, and the hype for Batman v. Superman: Dawn of Justice was that much more intense. Sure, Superman may not have ended in the best of places at movie's end (dead and buried), but the imminent arrival of November's Justice League seems to herald the return of the Last Son of Krypton. Each new DCEU movie has worked to expand the shared universe, but while Superman was in Dawn of Justice and will have a role to play in the superhero team movie, many fans are still hoping to see a true Man of Steel sequel.
In this universe, Superman's story and solo career as a hero has only just begun, and a lot of people still want to see what a proper Superman sequel would look like, and how it could explore this new and evolving superhero who is only just coming into his own as humanity's ultimate savior. The question, then, is, who should Superman face? What villain would give Superman an actual run for his money?
There are many classic Superman villains in DC's library that would be easy adapt that longtime comic book readers would love to see on the big screen like Brainiac, Metallo, Bizarro, and Cyborg Superman to name a few. But actually, when you consider all of these options, there is only one logical villain to have as the main antagonist in the film—Black Adam.