It was only when Zack Snyder's own version of the Justice League was released that viewers got a better idea of what his future plans were for the superhero ensemble. Making Superman evil is really hot right now as we've seen in the likes of Injustice: Gods Among Us and Suicide Squad: Kill the Justice League. Maybe it's the fact that Superman is the symbol of goodness that makes experimenting with an evil Kal-El so exciting? After all, the idea was that Superman would become evil in future Justice League films, signed Zack Snyder. Now he has talked a little about what the idea behind this looked like.
"He was going to have to succumb to the Anti-life, be destroyed, turn the clock back, and then get his chance for this battle against Darkseid [...] that would have finished his trilogy of becoming this guardian, and sort of, return him to his humanity."