I think that you might really enjoy The Graveyard Book, by Neil Gaiman. It's YA, and I think it fits your interests pretty well. I'm not usually into darker things but I loved it! Here's the tag:

After the grisly murder of his entire family, a toddler wanders into a graveyard where the ghosts and other supernatural residents agree to raise him as one of their own.

Nobody Owens, known to his friends as Bod, is a normal boy. He would be completely normal if he didn't live in a sprawling graveyard, being raised and educated by ghosts, with a solitary guardian who belongs to neither the world of the living nor of the dead. There are dangers and adventures in the graveyard for a boy. But if Bod leaves the graveyard, then he will come under attack from the man Jack—who has already killed Bod's family . . .