Just a tip: If you choose the black robes, you have to search for the poison creator when you go search the traitor. If you kill the traitor, you'll not became Great Mage because the person that have the power above the potions you treath you for let him win.
Sorry for me english, but I hope this can be usefull to win the last badge.
 "Book of Mages: The Dark Times"){kind=icon}