Nightbreed is an oddity in movie history
Although I like Nightbreed a lot, it's a movie that feels incomplete, not only due to the fact that it was heavily edited, but also because, well, it was intended as the first part of a trilogy. Barker had envisioned it as "the Star Wars of horror". Ambitious.
It's interesting. The majority of movie trilogies/franchises have been accidental. Star Wars, The Godfather, The Matrix, Back to the Future, Halloween, A Nightmare on Elm Street, Hellraiser, etc. A movie becomes a surprise hit, and the studio wants to make a sequel. Generally, sequels suck and are unnecessary. There are good sequels, sure, but even the best ones are still unnecessary.
Nightbreed is an oddity in movie history... a movie that actually needed sequels, and didn't get any... Shame, the world would have been a much better place with less terrible Hellraiser sequels and two Nightbreed sequels.