In a recent exclusive interview with Forbes, Man of Steel director Zack Snyder talked about the development and impending shoot for the Superman reboot’s forthcoming sequel, which may or may not be titled Batman Vs. Superman, among many topics of interest to fans of comics and superhero films.

One of the subjects that inevitably came up was exactly how the idea of pitting Superman against Batman in the much-anticipated sequel first came into being.

You can read what he had to say below.

Though the tentatively titled Batman vs. Superman was pushed back an entire year from its original release date, director Zack Snyder and WB are still working hard to build a great cast. Today they have added Oscar-winning actress Holly Hunter, 300: Rise of an Empire‘s Callan Mulvery, and Captain America: The First Avenger‘s Tao Okamoto.

Deadline reports that the roles have not been specified but they do not have comic book origins, instead these roles have been specifically created for the film itself.

Even though the yet untitled Man of Steel sequel, which we still are referring to as Batman vs. Superman, has had its release date pushed back to 2016, the film is still on schedule to start shooting this year. Fans are eagerly awaiting any concrete information with the plot and of course we’re all holding our breath in anticipation of seeing the new Batman costume design.

While out promoting 300: Rise of an Empire, the latest film the fan-dividing Zack Snyder has produced, The LA Times got the director to open up a bit about what we should expect to see with Batman vs. Superman, including a tease about the film’s plot, casting, and geeking out over the costumes.

Jesse Eisenberg will star as Lex Luthor with Jeremy Irons as Alfred in Zack Snyder’s untitled Man Of Steel sequel, according to Warner Bros. Pictures, who announced the news today.

Eisenberg and Irons join the cast of what’s been referred to as Batman vs. Superman, which will have Ben Affleck as Batman/Bruce Wayne, Gal Gadot as Wonder Woman/Diana Prince, and Henry Cavill reprising his role as Superman/Clark Kent, with other returning stars Amy Adams, Laurence Fishburne, and Diane Lane.

Recently Dwayne Johnson met with executives at Warner Brothers about his potential involvement in a top secret DC Comics movie project that may go into production some time this year. According to an unnamed source for Latino Review that film could very well be the studio’s eternally gestating Justice League, which was originally supposed to be filming for a summer 2015 release before the lack of a decent script compelled the studio to shut down development and shift their resources over to a Man of Steel sequel that would have Superman (Henry Cavill) going head-to-head with Warners’ other big DC moneymaker Batman (Ben Affleck).

The word is now going around Hollywood that both the doubly eponymous Batman vs. Superman (name subject to change) and Justice League will be filmed back-to-back and be released within a year of each other. Supposedly this is because the studio wants to capitalize as much as possible on the filming time they have with the busy Affleck, Cavill, and Johnson.