There are no special ''powers'' that come with an aura. As for unlocking, i assumed to be able to sense, or see an aura.With that said, there are many ways to accomplish, this. I suggest search it up, and check out, the following link as wel!
To possibly see an aura, get someone to stand in front of a light colored wall(White preferably). Close your eyes, and visualize yourself seeing one aura, what is it's color? What may it reflect? Next open up, and see if you can see one. It is typically around the shouldes and up. Good luck!