If you watch the video on warcraftmovies.com http://warcraftmovies.com/movieview.php?id=173471 swifty spell reflects a deathgrip and it pulls the DK to him. Unless they changed it you have to keep a shield equiped for the duation of the spell reflect otherwise it falls off. So you shouldnt be able to spell reflect while bladestorming. But if they changed it i could be wrong!