Left, right. North, south. Eastern, western. There’s an opposite for every position, be it political, religious, or anything else. The same is true of stories. The protagonist has an antagonist. There’s always a villain to face, an outlaw to bring to justice, a bomb to diffuse. The list goes on.
Some antagonists are evil personified. They act for the sake of causing chaos and mayhem. That’s great for a few stories, but be honest. Who is your favorite villain? Is it the cartoon caricature twirling his mustache and laughing maniacally? Or do you prefer someone with a tragic backstory whose actions could almost be justified if they weren’t so outrageous?
What makes someone a villain isn’t always about what they do. A lot of times, the only difference is your perspective. For a mild example, look at politicians. I bet you can name at least a few you find completely terrible. Meanwhile, others may totally adore those same ones. It all depends on your perspective on current events. Even the vilest people in history had admirers who held a certain point of view.
The same should be true of story antagonists. You don’t want some two-dimensional guy everyone hates just because you slapped on a Bad Guy label. What motivates the antagonist to do things others wouldn’t? What drives them to see a blurred line between right and wrong? What makes them a hero to themselves and those following in their footsteps? What would you see if you changed the perspective of the story to their mind?
Perspective is everything. As writers, it’s our job to know every perspective within our story. Even if you only give readers a glimpse of that, it ought to be enough to give all your characters depth. And while you’re thinking on that, maybe apply those same questions in the real world. You might be surprised by what you discover.