The Hollywood Reporter claims Brainiac was set to be the villain of the film.
Brainiac has been a popular choice for a future Superman film.
Brainiac is a robotic genius known for stealing knowledge and cities from around the universe.
James Gunn's Mr. Myxlplyx, an imp from the fifth dimension, could be a unique villain for Superman to face.
Other potential villains include Mongul, Lobo, and Metallo.
Dwayne Johnson was reportedly pushing for Cavill's return to the role of Superman at the time the script was being developed.
The worldwide box office for the original Man of Steel film was $389 million.
Cavill has since exited the role of Superman after many troubles.
Cavill did not have many villains to face as Superman in the original films.
A fresh start for the Superman film franchise could lead to the best adaptation yet.
It is unknown if any of these reported plans for a Man of Steel sequel will come to fruition.