In the Forgotten Realms, where I usually play, I was thinking of something like an unwilling Chosen of Beshaba, with both the good and bad aspects of that. (In South America it's called 'mufa' in colloquial language, 'moopha.') My idea was to make a cowardly kobold, more roguish than arcane but with maybe some levels as a sorcerer to make all potential builds apply. I'm trying to build a character who suffers a strange and inexplicable stigma that attracts misfortune to all the people around him.