However, it also allowed him to achieve one of his biggest dreams for the superheroes.
"Once we had committed to that ridiculous idea... it was only then that we were like, 'OK, that implies that a universe exists where Batman and Superman exist together," he said. "I am and have been obsessed with the trinity and really wanted to see the trinity, that being Batman, Superman and Wonder Woman, in a single moment."
Snyder added that by allowing the two heroes to meet, he also set the scene for the whole D.C. universe to evolve film-wise. ("I know it seems obvious in the comic book world but it had not existed, really, in the movie," he said.) Snyder also admitted that he was nervous that it would be difficult to do that, as it would involve so many filmmakers to "play nice."
"That’s the luck and sort of serendipitous nature of this movie that’s allowed the worlds to coalesce," he said. "It became a plan and it’s becoming a thing but it was only in its infancy that we realized, 'Yeah! Oh my gosh, this can be a thing.'"
His producing partner, Deborah Snyder, echoed the sentiments.
"We wanted to set up and introduce these characters but we also had a really rich story to tell," she said, "so it was a careful balance about telling this story - the Batman and Superman story - and giving a little hint and a tease of the Justice League that's yet to come."