Board Thread:Speculation House/@comment-73.140.18.107-20160909055159/@comment-74.140.202.65-20160913235717

So, we've established that Aura is like Health and Health Regeneration. A person with lots of Aura can take more hits (because of more HP) and can recover faster (because of rapid health regeneration). This is a lot like a video game. And, in most games where statuses are in effect, there are certain circumstances where a character's Health Regeneration can be halted or a character can consume something and be poisoned. Suffering from poison may chop away at the user's Aura depending on how much is consumed or how badly they've been poisoned. The same types of status effects can be applied in such a way that ables the user's aura to regenerate faster or to withstand more damage.

So, I think it is very possible and this does leave them vulnerable. Aura's, like HP, can run out. And, once it gets to that point, that's nothing you can do but wait until it regenerates.

As far as surgery goes and for turning Aura on/off, I think a person's Aura can be bypassed. You don't have to beat someone until they reach 0%: just numb them with a pain relieving agent which will relax the muscles, slow the reaction speed. and lower the person's defenses to where performing surgery wouldn't be a problem.