Books in the Dark Creatures series

The gods chose two unsuspecting players as their pawns in what was supposed to be a simple game of Dark Creatures, a game replete with dark things from a world gone mad and forgotten gods that play with life and death for their own amusement. When the rules for winning are ambiguous, the human beings are suddenly caught up in a contest of good versus evil and their game begins to spiral out of control.Now the cost of losing could mean the end of humanity and the very world itself.