But being the mirrors for each other's souls has a cost: by the time they part from each other, the individuals in the mating pair have become indistinguishable. Before their merger, they each yearned for the other; as they part, they part from the self. The very quality that attracted them to each other is also, inevitably, destroyed in their union.
Ken Liu, The Paper Menagerie and Other Stories
cost, merger, mirror, other, self, soul, union