I started game all over and lost everything including character build (from demo), and had to go through the stupid tutorial again. Upside to dragon side I just kept hitting start and skipped most of the movie parts.
You can do it right after you make your decision in regards to the final battle in the Everfall.
Fair warning but you'll want to do everything you can first before that fight because I couldn't find a way to continue the game afterwards. It forced me to do NG+ --- Gamertag: LordReider Ambition is just a weak excuse for not having the sense to be lazy.
since everyone isnt answering your question here it is after the final battle in the everfall and you become the seneschal use the godsbane blade --- XBOX Live Gamertag: C5150Angus Pokemon White - Quinn/FC 1807-1966-6432