Brainiac, Supergirl and Bizarro have all been rumored to be making an appearance in the in development direct sequel to 2013’s “Man of Steel”.
Heroic Hollywood reports that the alien android Brainiac is the current favorite to serve as the main villain and aims to get his hands on the codex – the macguffin Zod was also after in the first film.
In order to do this, he first tries to take it from within Kara Zoe-El/Supergirl who was introduced in a “Man of Steel” prequel comic. To do that he creates Bizarro and sends him after her.
The site claims it is the inclusion of Supergirl in a prominent way that got George Miller interested in the project. No script for the film exits, only a pitch Snyder and writer David Goyer gave to the studio says the report.