I too don't think an "anti religion" would work; it should be a religion in its own right, providing the basic things a religion might provide in BM: temples, shrines, priests, and a framework or context in which these three things make sense, descriptions of appearances and functions thereof.
Worshiping a human *as* a god could well be done.
I would focus on the "serious" aspect of it. Ask oneself: could this be a real religion? Could people really do this, if the world was like it is in BM?
Given that we have things like: undead, monsters and daimons, these too should be accounted for somehow. There should be an explanation for their existence, or at least where they stand cosmologically. The Adgharhin Way in FEI did this fairly well, if I do say so myself.
With regards to gods or goddesses, I don't think its necessary that they exist in name. They could be unspecified nameless gods, or spirits of ancestors, or Bloodstars. But in any case there should be someone or something that one could offer prayers, worship or devotions to, something that could roughly (though maybe not specifically) called divine. Even if such prayers, worship or devotion is borrowed from other religions or from pagan/folklore/superstition.
These are just my thoughts.