Hello! I don't know hardly anything about kpop, so I'm sorry if these are way off from your taste. I'm assuming you don't want any metal lol. I listen to a lot of spooky/dark?/fantasy themed stuff so these might fit any of those stories! I'm assuming you're looking for something to listen to while writing/ for inspiration?
Here's one that might fit more than one of your stories if you're into piano/violin and instumental:
Peter Gundry has a bumch of dark compositions that would also work with the themes you've listed.
Deaftones is also pretty solid for mournful dark tones. :
Glass jaw is more punk, but this one is slow and spooky:
More fantasy esk. Again more instrumental:
This one and exxus by Glass Animals have similar vibes (spooky/ritualistic):
This one is metal, just incase you were into it, I don't want to assume:
Electronic. Rezz almost only makes spooky stuff from what I can tell:
This one is more of a pop vibe, but still has darker lyrics:
I have a lot more, but I don't want to make this post a mile long. If I'm not way off from what you're looking for I could always DM you others.