Board Thread:General Discussion/@comment-24155619-20140711014702/@comment-3257939-20140713052637

Most likely because she has never been properly trained with real Grimms like when she didn't knew about that Boarbatusk or how to fight it. But it couldn't have been years ago, Weiss is a teenager and a woman, she can't just look exactly how she did years ago, not even a single year.

I'm saying it mostly because of how even Jaune was able prevent heavy damages from the Ursa which is literally a giant bear with a hell of strength and Ruby also had no idea about the upcoming shot from Roman (if she had, she would have dodge it) so she couldn't have focused her aura in an instant to protect herself. That's why I believe that since Weiss focuses her aura into her attacks, she lacks the ability to use it as a defense to protect herself. But since Jaune is able to do it naturally, then, it may not be a lack of training but simply that her aura is not suited for defense. Those are my main ideas of why auras vary from people.