So, about an hour ago, Ben Affleck posted the following short video of an actor dressed like the DC comics character Deathstroke to his twitter:
— Ben Affleck (@BenAffleck) August 29, 2016
Now Affleck is currently filming Justice League, where he continues to appear as Batman/Bruce Wayne, so the obvious implication is that the character of Deathstroke will show up in the movie. On the other hand, this could just be a costume test for the untitled Batman film Affleck is helming down the road. On the other other hand, maybe Ben Affleck is just messing with us.
Personally, my money is on “Montage of Batman fighting villains” in the beginning of the Justice League film, but that’s just a guess. Either way, it looks pretty cool.