Negative entropy is the opposite of entropic energy; the raw energy of Chaos. It came about from creating order and stability where there once had been nothing but change and entropy. When Creationists made worlds and populated them, they turned entropic energy into negative entropy.
By the God Era, the work of Creationist had become much harder.
It was easy in the beginning, you could shape a world in under a year, fill it with dull sentients in five. Now in this new era, the Age of Gods, the system is girded with energy, balanced.
Theologians define lawful beings as ones with more negative entropy in them than its opposite. Academicians that delve into the secrets of the energy types say that anything with permanence has a trace of negative entropy it, for if it did not, it would be drawn back to Chaos.