I've had this fun idea for a god-type character a while ago, and have been playing around with making some sort of story around. Essentially, this character would be the Lord of Twilight - operating as an agent caught between light and dark, balancing on the fine point of things, seeing the world in shades of grey. This guy would be sometimes a villain, sometimes a hero, all working towards his goal of balancing the world order. Able to work through any area in which there is a shadow, a merging of light and dark. He would be both a help and a hindrance to the protagonist at different moments.