It would be extremely cool if the power each god has is directly linked to the worship said god receives. For example a mortal may ascend to the divine by gaining followers or a divinity could sink to mortality by losing followers. It might even be cool to have a bit where a fallen deity enters the picture, he/she may talk about spending centuries a very powerful being then slowly declining to the point that for the last few decades he has been worshiped by only a few (or ONE) person and now he has no worshipers and has become mortal again.