Hey, how switching the piety costs of humility and enlightenment, and have humility knock you back to level one sound? If it makes sense, then how about, if a dungeon boss is killed by a level one hero, the glowing guardian "beams with pride" which gives you a free 100 piety. (keep in mind, at this point the dungeon is already basically done). But, if dracul's altar is on the field undisturbed, then he summons a mirror image of you to fight, so that you can attempt to get to boss trophies in one sitting!?
Even if this idea doesn't fly, I was really interested in the idea of having the Gods have relationships with each other, and have that relationship actually affect, or be affected by the players actions. Maybe desecrating the altar of an "allied god" would cause greater negative effects or a smaller piety plus? And destroying enemy Gods would have your God give you a positive effect (not a boon, just the opposite of the usual negative consequences) or simply more than the usual piety. This would probably throw balance into the wind, but I think it COULD be possible to work out. Any thoughts?