10 Characters The DCEU Wishes It Could've Introduced Differently
4. The Flash
Only a mild issue this one as it's just that little clip in Dawn of Justice isn't it. Where Flash appears in some sort of weird time vortex to try and warn Bruce Wayne about "him" and how he "needs to find us". At the time it was a really exciting little cameo that showcased Ezra Miller in the role and hinted again about a much wider universe that was out there to be captured on film.
Except it... didn't... go... anywhere? Whatever long-form idea they were planning to pay off with it never actually materialised in any subsequent films and the message still just sort of hangs there unexplained. Miller's performance in Justice League was perfectly adequate - even when compared to the long-running TV portrayal it was going into direct comparison with - but this loose thread smacks of their long-term planning with short-term thinking.
Story goes that there was never actually a pay-off for this specifically in mind when the scene was shot, and that Snyder and Co planned to figure it out as the movies grew around them. If that's true then in all likelihood we'll never find out what he's talking about.