At some points in the trailer, we see a creature destroying MidwayCity subway.
First glimpse: We see it from behind shooting "tentacles" from his hand. You can notice a golden piece of armor on his forearm
Second and third glimpse: In what appear to be the continuation of the previous scene, we can see his profile (still shooting tentacles from his hand) which look like an human shape wearing a big mohawk going down on his back. The whole creature looks to be made of magic or energy (minus the face but we get back to that later).
Those two clues leads us to O.M.A.C.
O.M.A.C. was originally created by Luthor (using Brainac tech) and the government to track down and destroy metahumans.It fits pretty well with DCCU climax. Plus, wasn't Luthor supposed to be in this movie?
One last weird thing about the supposed OMAC. His face, who's unlike the rest of the "costume" is not made of glowing energy, look an awful lot like Jared Leto's Joker...
What do you think ?