Titania

Just think of her as the manipulative player behind the scenes who just wants to watch the world burn (or freeze in her case).

Very hard to get her real opinion out of her. She's been around for a long time, very unpredictable, recently took a liking to the human world wondering what fun games she could play there: for example granting some people special abilities, pitting them against each other etc.

Grimm is currently somewhat trying to stop her but he's got nowhere near as much experience and forsight. So he kinda just became a player in her little game

However there are some other people who might turn the tides, who knows.