User blog comment:Thesupremejoyner98/Grimm that can cut through aura/@comment-3146930-20150113222323/@comment-25555436-20150113224651

I don't think so, exactly.

-Aura greatly reduces damage, improves the speed at which injuries heal, but it's not going to simply block everything. One can still feel pain, and can still get a small mark or 2 because of an attack. Aura only makes that attack less dangerous and non-lethal.

-Jaune may supposedly have tons of Aura, but remember his (by that episode) was completely untrained and undeveloped. As such, it's not "working" at full capacity. While the rest of them have more experience, and likely trained use of their Auras for defense, Jaune hasn't. He doesn't know how to use it, nor has he ever trained it. As such, it's much less effective than it should.

You may have the best sword in the universe. But if you have never ever used a sword nor know how to use one nor ever trained yourself in the use of a sword, said ultimate sword will be much less effective than it should be.