The Magic of Willow

In Willow, there are three magical objects and only one magic system. In Ghostbusters you have 16 other ghost hunting equipment each with its own technological powers that would fall apart if they piled on more of them. You can do it in a novel or TV show but not feature film writing. Big world, small window minimize your cast; don't make us need to follow along with all the DC mythology. The last one is enough for your movie: Four or five creatures in your movie is enough. My recap is best practices for fantasy screenwriting in Jimmy George's opinion.