Ben Affleck and Zack Snyder have already confirmed that Deathstroke will exist in the DC extended universe. But the assumption was that the villain would be making an appearance in the solo Batman film. While rumors claimed that the villain might make an appearance in Justice League, they were limited once again to assumption.
Like Ben Affleck before him, Zack Snyder couldn't contain his excitement while working on the next DC installment. The director took his excitement to Twitter to show him rocking some Batman Cosplay while reviewing storyboards.
With the advent of Photoshop, or any image editor with a zoom tool, the digital storyboards were (of course) blown up. And what was discovered?
Deathstroke in Justice League Storyboard
The photo above was posted by Zack Snyder to Twitter. There are a lot of cool aspects to this photo, such as Snyder's mad style, but the importance of the storyboards is clear. Twitter user TheDCEU cropped and zoomed in on the director's tablet, making for a big discovery. Deathstroke! But does having Deathstroke in a storyboard for Justice League make him a guarantee for the film? Well, nothing's a guarantee, but it's pretty strong evidence that, yes, we can expect to see the villain.
— DC Extended Universe (@TheDCEU) September 29, 2016
Deathstroke in Post Credits
The theory on what is being shown in the storyboards is a meeting between Lex Luthor -- hence the bald head -- and Deathstroke. While having Lex Luthor having a big returning role in Justice League sounds like a risk considering BvS, it does seem fitting that this is a post-credits sequence. How better to introduce the next Batman villain than showing Deathstroke and Lex talking to team up to take on the caped crusader. Let's not forget that it was Batman that foiled Lex's plans of keeping Martha hostage. The rescue scene turned out being one of the best sequences in the entire movie. But I digress...
If you analyze each panel, you will see that it looks like Deathstroke is contemplating something, such as an offer by Lex. And it looks like things kick off with Deathstroke on his knees. Could it be that the villain was recently defeated, or is the character known for some sort of worship? My knowledge of DCEU villains is obviously limited to theory and conjecture.
While some might think that the reveal was a slip on Zack Snyder's part, we recently discovered that the director's attention to detail is uncanny. So let's assume this Twitter post from the director was just one genius way of confirming a specific character's existence. No press conference needed.