Haunted does not mean bloody in my opinion. Try making the palette with a dark blue tone (Kinda like this) to make it look gloomy. Of course it may have a tiny bit of blood here and there.
Removed some blood, put some fog and mega darken the area:
Want progress on 100 Rooms of Enemies: The Nightmare Edition? Go here to see.
(rip my other userbars momentarily)