Antagonist
Character Role Analysis
The Antagonist
The antagonist in the journey can sometimes be a villain, like Darth Vader, or it can be an more nebulous threat, like a dragon, a plague, or starting a political discussion at an overcrowded family Thanksgiving party.
Whatever it is, it's the thing the hero has to stop before it destroys every last vestige of the world.
The thing is, because the antagonist is part of the greater universe, he, she, or it is a part of the hero too. (Dang, Campbell. You're deep.)
Antagonists rise from the shadows of our own mind, and we don't beat them by conquering them; we beat them by understanding that they serve a purpose in the universe, too, and that we all have the capacity for the evils they inflict. That understanding brings enlightenment, and with enlightenment—poof!—the bad guy disappears.