The Unmaker

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

Aside from generally opposing all life, the Unmaker is the nemesis of one Alvin Maker in particular.That Alvin is heavily magical doesn't matter, but he is a Maker, a person of exceptional power diametrically opposite in purpose. Furthermore, there's something to be said for the argument that Alvin is affiliated with another higher element - a not particularly subtle detail, given the Unmaker's nature. It makes repeated attempts on his life, mostly by inducing accidents at Alvin's childhood (especially by drowning, since eroding water has a natural affinity to it) and increasingly by influencing people later on.

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.