I am looking for a novel in which there are several factions of different mages such as the 'red faction' that has to do with fire and and truth.

The main story is about a boy who joins the fighting mage's faction / house. In this house everything is trying to kill you. you have to sleep lightly at night or the shadows attack you, you can't sit too long in the healing pool before little monsters try to kill, if you want to eat you have to fight a man-thing made of leather to prove that you are improving etc.

The boy's mentor is also a crazy guy who has dolls that help him and talk to him.