Crimson desires by paranjae is the best one I read so far. I saw it was already recommened with a link so I didn’t put one in my comment.enjoooy ^^

Idk if you ever read any of these but since you were asking, these are some tiny bits of my favorite Fantasy, Vampire, supernatural, dragonau, avatarau, ABO alternate universe :

All Fanfiction by FishMeAnExo or Hyperionova. Mostly SeKai ship.

Dead until evenfall
https://archiveofourown.org/works/5291279/chapters/12214307

King's lost prince
https://archiveofourown.org/works/7592749?view_full_work=true

Artfull sin
https://archiveofourown.org/works/9109522/chapters/20706139

All the Prodigialis series
It's not about vampire but fantasies at it best.

Fanfiction by Parkanjae
mostly write story about fantasy and supernatural.
https://www.asianfanfics.com/profile/view_author_stories/659879/VO

Crimson desires
https://www.asianfanfics.com/series/view_series/659879/1184

Fanfiction by Taelighted
Running with the wolf
https://www.asianfanfics.com/story/view/662881/running-with-wolves-action-fluff-magic-werewolves-exo-kai

Fanfiction by Shewolf94
https://www.asianfanfics.com/profile/view_author_stories/906406/L

Fanfiction by jas1922
https://www.asianfanfics.com/profile/view/816305
Favorite :
-The lost heirs
-Pure blood with a pure heart (Harry Potter au)

There's so many more that I can listed in here but it will take a month to do so.. I hope you'll get inspiration that you need.

Hello! I will like to share a fic which is unfortunately not based on exo but it is a very popular and classic fic in the shinee fandom nonetheless. I think you've probably heard of it but this is the one: https://www.asianfanfics.com/story/view/253553/the-beast-comedy-jongkey-romance-shinee-vampire

It was first published 7 years ago and the author kind of stopped updating (for more than four years) but it's just such a great vampire fic. disclaimer: jong is the main pairing so don't force yourself to read if you're uncomfortable.

Okay so like there's no vampires in this one but it's a gem idk if you've read it already
Running with wolves by taelighted
There's a lot of chapters aha
If you're writing fantasy, then there's a lot of possibilities because of all the alterations each culture has and all that
Sometimes authors tweak the legends or add smth in order for it to make sense or for plot reasons so there's no direct right or wrong
Have fun writing :D

Fitingggggggggggg author nim where you afraid you are the best

un's story! like all! everything is worth taking an inspiration of! but i like the reason to fight;)

Vanillasushi’s kiss me drink me! It is so good! And it is very nice of you to research first, but i hope you dont afraid to make new things and enjoy the process hehe all the best for u!

Here we go for fantasy: https://www.asianfanfics.com/story/view/1121539

i really don't think u need to read any stories to get inspired because you're an awesome writer and if u find the perfect plot the story will come natural to u ^.^ Have fun on the way!^.^ ♡♡♡♡♡♡