After reading a few of the other ideas that people have posted about the gods being like people with issues and downsides I think it woud be nice to play off of that. Having gods with aspects that relate to them that go together and then one that does not. Having that one thing that they are forced to be that throws off their balance as a god. Like god of war and destruction has to also be sometimes the god of compassion for the weak. Making them have to change gears so to speak so that they can't be all representative of a aspect with out some kind of flip side to it that they have to do now and again as it is part of their nature.