The Hero of Ages (Mistborn, #3)

by Brandon Sanderson

Preservation’s desire to create sapient life was what eventually broke the stalemate. In order to give humankind awareness and independent thought, Preservation knew that he would have to give up part of himself—his own soul—to dwell within humankind. This would leave him a tiny bit weaker than his opposite, Ruin. That tiny bit seemed inconsequential, compared with their total vast sums of power. However, over eons, this tiny flaw would allow Ruin to overcome Preservation, thereby bringing an end to the world. This, then, was their bargain. Preservation got humankind, the only creations that had more Preservation than Ruin in them, rather than a balance. Independent life that could think and feel. In exchange, Ruin was given a promise—and proof—that he could bring an end to all they had created together. It was the pact. And Preservation eventually broke it.