I am going to play in a short campaign soon, and he asked me to play something interesting. SO I started wandering through my old pics and came across a Games Workshop pic of the Green Knight. So I came up with this idea of a tiefling who becomes convinced that his presence is a sign of the worlds sin (could you blame him, being treated as he is) and sets out to right it. He chooses the path of the knight because he may hide his features, and yet not work from the shadows. Somehow he ends up following a very specific ethos (LG) and the powers of the universe gave him the powers of a paladin. He now hunts undead, demons, and those who would corrupt the world he now has chosen to protect. The religions of the world do not trust him, but he fights on nonetheless.