User blog comment:Thesupremejoyner98/Grimm that can cut through aura/@comment-9090085-20150114064213

No.

And I don't mean that your scenario is bad, in and of itself, but that I don't think it fits in RWBY; mostly because it ignores the purpose of Aura in my mind.

That purpose, as I see it, is two-fold:

The first point of Aura is seen in a number of fights, like allowing Roman to come back swinging after getting slashed in the chest in Black and White; or Blake and Adam to blasted out a train car by a Big F-ing Laser in the Black Trailer wihtout dieing; or just making Yang's fighting semblence appear OP instead of suicidal(could you imagine Yang getting hacked up and with brocken bones in order to use it? Sure, it would work, but she'd have to go to hospital after every fight).
 * To make cool fight scenes where getting hit once doesn't mean that the fight is more-or-less over(you know, like in real life).
 * To allow people to lose fights and not die(similar to how Knightmare Frames in Code Geass have ejection seats).

The second point much more meaningful to me: in No Breakes alone we see the WF Grunts, Yang, Weiss, and Roman all come out of their fights uncosious instead of dead thanks to Aura; of course, this didn't prevent their opponts or the Grimm from finnishing them off while they were unconsious, but that's why they tried their best to win.

Aura creates an interesting decomity to fights for me: on the one hand, the attacker will fight all out even if they don't want to kill, because their opponents Aura will protect them from lethal damage; while the the defender will try their best to not get hit, because their Aura will not always protect them. You see, whenever someone's Aura reflexivly activates to shield the user from damage, it is reduced, and after getting hit hard enough and enough times it runs out, leaving them exausted or even helpless(a little like a fight without Aura). And even with Aura, getting slashed with a sword or punced in the face hurts(again, like a fight without Aura).