Freya Ishtar is an amazing writer, who in general, but not always, writes with a supernatural and/or scarey vibe to her work. I recommend all of her work, but two which well suit your criteria, you can find here:
The Invisible Ones Rated
MA
-and-
Stealing Heaven Rated
MA
She's also a published writer of her original story, "The Summoned (Tales of the Phantom Court)" which is also spooky and an amazing read! If you are interested, you can find it here:
The Summoned Again, this is what I'd call an
MA read.
