As you can tell, I'm new to manga lol
I've read Reiko the Zombie Shop and I LOVED it! (I saw it mentioned in a magazine, so I decided to read it after seeing the cutout of Saki's hand bleeding like a fountain)
And I've read Satanister and I loved it! The cross symbol irked me a bit, but...it was really cool.
Any other manga like those? Bloody, gorey, lots of death...
I've looked at the other recommendations and I'm not into yuri romance. Please, no simple manga. I like horror.