When Wonder Woman came to man's world for the first time in her first standalone movie, she had one goal: kill Ares, the god of war. Ultimately she was successful, but that wouldn't be the last time we'd see the Olympian antagonist in the DC Extended Universe. It turns out that Ares made a brief appearance in Justice League months later, and you can take an up-close look at his design in that movie below.
This photo comes courtesy of Nick McKinless, the man who played Ares in Justice League. Along with showing how he looked in the Ares costume, McKinless also shared photos of the god's belt and badass horned skull helmet in the Instagram post. War is always hell, but with a guy looking like this, pray he's on your side rather than an opponent charging to behead you.
If you're wondering why Ares looks so different than he did in Wonder Woman, it's because rather than showing up in the present day, the Olympian appeared in the flashback sequence depicting Steppenwolf's first attempt to conquer Earth with his Parademon army thousands of years ago. Ares was joined by fellow Olympians gods Artemis and Zeus (Ares' father), and they fought alongside humans, Amazons, Atlanteans and even a few Green Lanterns. See if you can spot Ares when re-watching the battle below.
Although Nick McKinless physically portrayed Ares in Justice League, you won't see his face in the movie, and not just because that helmet is partially obscuring it. Because David Thewlis portrayed Ares in Wonder Woman, the Justice League VFX team superimposed Thewlis' face over MicKinless'. Continuity matters, after all, and these gods are lucky enough to not age like us mortals.
Obviously the original deity Ares is part of ancient Greek mythology, but as far as the DC Comics mythos goes, the character was first introduced in 1942's Wonder Woman #1, though it would be another four decades before he would regularly be called Ares rather than Mars. Outside of the comics, Ares has appeared in Justice League Unlimited, the 2009 animated Wonder Woman movie and Injustice: Gods Among Us (to name a few), but the DCEU Wonder Woman movie has unquestionably been his most significant, public appearance.
There, Ares disguised himself as Sir Patrick Morgan and manipulated both sides of World War I, but by the movie's final act, he adopted his more traditional appearance to fight Diana, who was revealed to be Zeus' daughter, thus making her and Ares siblings. Despite his attempts to convince Diana that humans weren't worth protecting, the heroine, empowered by Steve Trevor's sacrifice, chose love over war and destroyed Ares.
Although Ares supposedly killed all of the Olympian gods long ago, there are rumors that one might show up in Wonder Woman 1984, somehow having survived the God of War's genocide. But as far as Ares goes, there's no indication that he'll be brought back to life in the DCEU. Still, it was cool to see his younger self show up in Justice League and catch him at a time when he was still interested in protecting the world and not killing his fellow deities.