Justice League: 10 Ways It Sets Up The Future Of The DCEU
6. "A League Of Our Own"
Justice League's unforgettable post-credits scene sees Lex Luthor having broken out of prison and residing on a boat, where he's met by Slade Wilson aka Deathstroke.
Luthor then asks him, "Shouldn't we have a League of our own?", not-so-subtly hinting at the formation of a villainous stable commanded by Luthor, most likely the Legion of Doom.
This is further supported by Deathstroke's actor Joe Manganiello being recently spotted wearing a Legion of Doom T-shirt, and seems to suggest that Justice League 2 might involve a war between the Justice League and the Legion of Doom, not to mention the aforementioned presence of Darkseid.
It seems most likely that the Legion will be slowly formed over the course of the next few DCEU movies, with Aquaman and Wonder Woman 2 probably adding a villain to the mix each before the Justice League sequel brings them together.