Fool's Gold

Prolegomenon

They say that even in the nicest people of the world, no matter how selfless or saintly, there lies an evil. This evil, while mostly hidden from view, stirs within its host, waiting for its moment to strike. Control is a key step in keeping it from escaping, but not everyone's willpower is strong enough to contain its power.

Eventually, you'll either get worn down and give in, or you'll fight until it gives up. Either way, you're never truly in control.

People who get taken over lose it. They attack people, lash out, and basically break down until they're imprisoned, taken to a nut house, or worse.

There is, however, a name for this evil. Victims refer to the idea as if it were a living being. They call him...Bill Cipher.