User blog comment:Blitzxs/Cardin is one tough son of a mother/@comment-3257939-20140904184357

This is important. It brings a certain question: Just how durable are auras?

We can assume that when Pyrrha said that Jaune has a lot of aura, she meant that the amount he has is particulary large but he has on aura training so despite having a lot, it's weaker and drains faster.

Or, like you wrote, the Ursa was quite powerful and two strikes were able to drain as much aura as Pyrrha was able to drain from Cardin during the entire fight.

Or that Cardin simply has more aura than Jaune and he is not special in aura in anyway. Maybe it was just her saying that because he was able to heal that wound but look it at this way: Cardin has 500 poins of aura, that's quite a lot. Jaune has 200 points of aura. Not as much as Cardin but still impressive.

It's really a topic that should be explained in one of the World of Remnant episodes. We don't know how that works, apparently, everyone is quite invincible in a way since they're able to survive tons of damage.