By the time it ends, Zack Snyder's Justice League has featured a host of supervillains in brief cameos, that were originally meant to set up future spinoff movies. One such villain was the master assassin Deathstroke, played by Joe Manganiello, who shows up briefly to talk to Lex Luthor at the end of the film. In an interview with ComicBook.com, Manganiello explained the tragic backstory for his character's obsession with Batman.

"You could kind of like infer from the proper Justice League end credit scene. Slade is summoned by Luthor, who offers a peace offering of information to Slade. So basically: Slade lost his son. And he blamed Batman for it. Batman had a hand in it. And Luthor summons him to his yacht. And gives him a key piece of information that Batman's secret identity is Bruce Wayne. So now he's setting loose this unstoppable force on Gotham City and Bruce Wayne."

Before the so-called "SnyderVerse" was derailed back in 2017 after Zack Snyder's exit from Justice League, Ben Affleck was meant to star in, direct, and write a solo Batman movie featuring Deathstroke as the main villain. In the past, Manganiello had explained that the film would have seen Deathstroke systematically breaking down Bruce Wayne's defenses by destroying everything, and everyone, that he holds dear. The actor described the now-scrapped project as a psychological thriller in addition to being an action movie.

"The Batman film was going to be kind of similar to like.. You know, imagine if David Fincher's The Game was real, you know? [Deathstroke] systematically dismantles Bruce's life and starts murdering all the people in it. Destroys his finances and just basically paints him into a corner... But it was like a real psychological thriller and Deathstroke was kind of like a horror movie villain, you know, like a shark, kind of like like Jaws."

It sounds like Affleck's Batman movie had the potential to be something really dark and special, which fans of the SnyderVerse would have enjoyed watching. Unfortunately, Affleck's poor experience on the sets of Justice League, coupled with the actor's personal problems around that time, prompted him to exit the role of Batman, which is when Matt Reeves stepped in to make his version of a Batman movie with Robert Pattinson.

With the restoration of Zack Snyder's Justice League, and Affleck confirmed to return to the DCEU as Batman for a brief cameo in the upcoming solo Flash movie, fans can once again hope to see the actor's Batman movie someday featuring the Dark Knight facing off against Deathstroke.

Zack Snyder's Justice League stars Ben Affleck as Batman, Gal Gadot as Wonder Woman, Henry Cavill as Superman, Amy Adams as Lois Lane, Jason Momoa as Aquaman, Ezra Miller as The Flash, Ray Fisher as Cyborg, Jeremy Irons as Alfred Pennyworth, Diane Lane as Martha Kent, Ray Porter as Darkseid, Ciarán Hinds as Steppenwolf, Jesse Eisenberg as Lex Luthor and J.K. Simmons as Commissioner Gordon. The film is now streaming on HBO Max. This news arrives from ComicBook.com.