12 Biggest Unanswered DC Movie Mysteries
11. Was It A Dream Or A Vision? - Batman V Superman
And come to think of it: what's the deal with Bruce Wayne's visions? Initially, it seems they're just random nightmares, but then the Knightmare sequence is very much presented as a vision of the future (the Ghost of DC Future, as it were). So are we to assume that someone is implanting them in Bruce's mind from the future?
If so, who? Only Martian Manhunter would really be capable of such powers in Justice League terms, and he's not confirmed for the DCEU (yet). Plus, this is a very particular, very precise sort of power, so it's not likely any of the other Leaguers just sort of learned it, or that Batman found a way of accessing his earlier self like some sort of Save Point.
Then to complicate matters, Bruce is visited by Barry Allen from the future (presumably using his Cosmic Treadmill), which turns out to be a dream, since Bruce wakes up from it immediately. But then he treats it like it actually happened, so he clearly thought it was more than the product of some over-indulgent cheese-eating himself.
We'll have to wait in the dark for now for clarification.