I think so long as the basic plot can be followed and the human heart of your story is relatable, you can go pretty wild. A good example is Star Wars. The plot is very easy to understand: basic hero's journey about young farm boy who goes on quest with wizard to rescue beautiful princess from the bad guy castle. But the stuff in that movie was completely bonkers for the time, nobody had seen anything like it! Star ships as big as cities manned by space nazis, farms that farm water on a desert planet where people drink blue milk and there are bars full of weird aliens listening to live jazz music, bickering robots, space wizard knights with laser swords, spaceship dogfights, a big evil cyborg samurai who breathes in raspy breaths.
This is the approach I take on Errant. At heart it's a story about flawed people and their relationships and the struggle over this magic sword. Everyone has weird hair and incredibly impractical oversized weapons and often odd fashion, and there are demons in gym wear that explode into rainbow sparkles and a political activist who wears an opera cloak and a bird skull mask, but so long as the main thing the story is about is the simple story of a terrible girl who turned a blind eye to the mistreatment of her friend for power and attention and how she's going to fix that, these weird elements are just flavour.