Support # of stacks of a specific aura

[dolphinspired]

Perhaps use "goal" in combination with "get-aura"? Or modify the "aura" condition to allow for a number of stacks, so that it can be used with other objectives as well? i.e.:

• Get 10 stacks of X aura (while in Y area)
• Obtain item X (while having 10 stacks of Y aura)