Need help finding an anime

I don't know if this is enough to go on but I saw one episode a while ago and recently wanted to pick it back up. It's set in a fantasy land (swordfighting and magic) main character is some kind of thief/rouge with white hair who can "steal Mana." Fight scenes are pretty awesome and look kind of CGI/3D. The story is about some kind of magic book that's killing the world and starts after the army loses to some sort of dark lord that rips the book. Really hope that's enough info, hope you guys can help and thanks for your time. :)