User blog comment:Thesupremejoyner98/Grimm that can cut through aura/@comment-3146930-20150113222323/@comment-3146930-20150113232022

I'm not sure which points you disagree on. You and I seem to think the same way about Aura, how it isn't an impenetrable force field and the user will still experience the impact (except maybe at a reduced level). I also agree that Jaune is pretty untrained in the use of Aura, but the only person to really show any high level of Aura control is Ren when he stops the snake (can't spell its name). Obviously the others have Aura training as well considering a Semblance is apparently achieved when Aura is trained to a high enough point.

Going back to Jaune, yes he is untrained but he still has Aura which probably took some of Cardin's punishment. However the fact that he has a bruise shows that Aura doesn't stop everything and unless you are someone at Ren's level, bladed or sharp edges will most likely get past a person's Aura. I'm not saying an attack will be lethal every time mind you, just that it can get past Aura if sharp or powerful enough. Sort of like a suit of armor having an easier time stopping a club than a sword.