(Update, 8/29 at 12:15pm): So it turns out the Deathstroke teaser is for another DC movie. The Wrap reveals the villain is confirmed to appear in Ben Affleck's standalone Batman film (he's directing and starring in it), not the Justice League project as previously reported. They claim Deathstroke will be the main antagonist in the movie opposite Batman.

(Original Story, 8/29 at 11:15am): Get ready DC comic fans, because Ben Affleck just revealed a major Justice League teaser. The actor dropped a clip on Twitter showing someone portraying Deathstroke, seemingly confirming the DC villain will have a part in the upcoming movie.

The teaser is pretty ominous, with Deathstroke looking menacing while walking through billows of smoke. But it's enough to build even more anticipation to what's to come for part one of Justice League, which Affleck is executive producing.

There's no word of who will play Deathstroke, who is known in the comics as a mercenary and assassin, and has gone head-to-head with Batman in the past. Affleck will reprise his role as the Caped Crusader in Justice League, which also stars Henry Cavill, Gal Gadot, Ezra Miller, Jason Momoa and Ray Fisher. Look out for it in theaters on Nov. 17, 2017. 

In the meantime, flip through our picks for the best villains of all time and check out these dope cosplayers at New York Comic-Con below: