French publication Studio Ciné Live have revealed this detail and a translated passage provided by ComicBook.com is below. It appears that Ares, the God of War, a major adversary of Wonder Woman’s dating back to publications of the 1940s, will be opposing Diana Prince (Gal Gadot).
“Behind these scientific formulas, there is a deadly gas that could well annihilate humanity. Now, it turns out that this is precisely the goal of Ares, the god of war. He is jealous of humanity, which is a creation of his father, the deceased Zeus (he was killed by Ares when he rebelled against him, with the help of the Amazons)…”
Wonder Woman arrives in theaters on June 2nd, 2017.