I hadn't thought of the fact that Kyubey's goal is to maximize the girls' despair. Wow. And not even having to distort their wishes, simply relying on humans' lacking self-knowledge, and that is part of what brings on the dark side of the fulfillment of their wishes--that speaks to balance of a kind too! If there is as dark a side to wishes' being fulfilled, as there is the way the wishers want it to be.