OK so after beating Wintertusk and Celestia I think Merle should give you a quest that says it's time for your final exam. Where you have to duel each of the schools teachers in their school towers excluding Cyrus Drake because we already had to beat him to get into Dragonspyre, unless KI decides to make him stronger. Than after defeatinbg each of the teacher's it's time to duel Merle Ambrose, and after defeating him you get the badge "Headmaster" or something.