The Unmaker

The Unmaker is the main antagonist in Orson Scott Card's alternate history/fantasy series The Tales of Alvin Maker, which were written from 1987 to 2003. Never directly confronted, it is a supernatural force that breaks apart matter and aims to destroy and consume everything and everyone. Essentially, the Unmaker is entropy as a conscious, destructive entity.

Aside from opposing all life, the Unmaker is the particular nemesis of Alvin Miller. Alvin is a Maker of exceptional power and prodigious creativity who enriches life by constructing both objects and social bridges, thereby threatening and thwarting the Unmaker. The Unmaker repeatedly attempts to do away with Alvin, at first by inducing accidents at Alvin's childhood (especially by drowning, since eroding water has a natural affinity to it), and later by influencing people to challenge and repudiate him.

To make something is to oppose the Unmaker, but a point often made is that this is futile. By natural law the Unmaker can tear down faster than any man can build. On the other hand, Making cares nothing about natural law. As Taleswapper reveals to a seven-year-old Alvin, the creation of what's known as the Crystal City could defeat, even destroy, the Unmaker. This then becomes Alvin's mission in life.

The Unmaker is usually undetectable to most people, though Alvin can detect its attention as a shimmering around his field of vision. It manifests when it needs to in order to tempt people into war and destruction, in which case it takes the most effective shape; a priest would see an avenging angel, a slave-owner a great overseer, etc. It won't appear to those who destroy willingly - they serve its cause already.