In August, Warner Bros. had put "Man of Steel 2" back in active development. However, very little information about Superman's (Henry Cavill) solo outing has since been shared by the studios. Despite this, speculations have been high regarding the sequel and some of them discussed the iconic villains that might be featured in the film.

According to We Got This Covered, the most likely candidate is Brainiac. A super-android that often claims to be the most intelligent being in the universe, Brainiac is often tied with the Kryptonians and their history. In the original comic books, he shrunk the Kryptonian city of Kandor and kept it in his spaceship as part of his collection.

Brainiac has reportedly been teased in the DC Expanded Universe which makes it likely he will appear soon. The viral marketing campaign for "Batman v Superman: Dawn of Justice" included a mock website for Lex Corp, and the site detailed the launch of Lex/OS, a type of computer OS that has gained a sentient conscience.

John Corben, who is also known as Metallo, is also a possible candidate, and according to the report, director Zack Snyder had stated in the past that, before "Batman v Superman" became as it is now, the film was initially going to be "Man of Steel 2" with Metallo as the main villain, hinting that this plan may still come to fruition.

As stated by CinemaBlend, Metallo was once a normal man but after a tragic accident, he was transformed into a cyborg that had a Kryptonite heart. This gave Metallo a significant advantage over Superman and is often regarded as one of Superman's most iconic villains other than Brainiac and Lex Luthor (Jesse Eisenberg).

The official release date for "Man of Steel 2" has not been revealed yet, but it is expected to premiere in 2018 or 2019.