The main character is some sort of "protector" where he carries something that has holy blood inside. He and other characters are trapped in a house/bar/hotel (can't really remember) and the bad guy is actually some sort of demon in human shape.
The protector drops small amount of blood on the floor of doors and windows, which creates an invisible shield that no evil can pass.
Demons/zombies attack them in a few waves and at the end of the movie the protector dies and a women character fills the same cup with dying protector's blood and becomes the new protector. At the very end, before she gets into a bus, she drops a drop of blood to bus door and after a while, in the middle of nowhere, a black guy is waiting for the bus and the bus stops near by him. But he can't get in so we understand he is the new demon bad guy.