7. Superman: Brainiac
There is one very obvious candidate for the villain of Man of Steel 2. Brainiac is one of the Big Blue Boy Scout’s biggest foes, and yet he has never appeared in in a movie. Which is a crying shame as Brainiac is such a versatile villain. They could either use him as the dangerous alien criminal he traditionally is, or reimagine him as a corrupted artificial intelligence, as some previous adaptations have done.
If DC are looking for comics storylines for inspiration in introducing Brainiac into the DCEU, they need look no further than the simply-titled Brainiac. For one, it’s another story written by Geoff Johns, who is now the creative head of the franchise. He could even adapt his own work for the screen.
Brainiac’s traditional shtick is that he shrinks cities into bottles and this story is the best one for portraying that as a terrifying event. In Brainiac, the villain targets Metropolis itself with his ultimate plan involving blowing up the sun. It’s a big, bold story with lots at stake, which should make it a natural choice for a big screen adaptation.
Brainiac also features Supergirl in a significant role, which would gel with the character's presumed existence in the DCEU. Man of Steel briefly featured an open Kryptonian pod, leading many to believe that Kara is already out there somewhere. Supergirl would be a great fit for these movies as the DCEU has an ever-growing strong female presence e.g. Suicide Squad and Wonder Woman (with Batgirl and Gotham City Sirens also in development).