I don't mean the instantly unfortunate mythological figures, the "you want to date me? gobble chomp you're dead" kind. I mean the "complicates his life in an interesting way" kind.
Carter (yes, for those of you who have been following along, it's one of those stories) has already had run-ins of various sorts with the Queen of Air and Darkness, the Puck, and Baba Yaga. In case that helps.