While looking through the new esoteric dragons for campaign ideas, I'm having trouble understanding exactly how the Aura of Protection ability of the Occult Dragon works.
The ability:
Protective Aura (Su)
A very young or older occult dragon has an aura that acts as a magic circle against evil, law, or chaos as a 20-foot emanation.
So when does the dragon choose if this ability works against evil, law, or chaos? When they get the ability upon entering the very young age category? Can they change which alignment they protect against? If so, how often can they change it?
Also, can the ability be suppressed if the dragon is cautious about exposing themselves? (say when using change shape to pass as a human)