The price your antagonist pays without seeing it
Your antagonist's path costs them a specific human ability, and the difference between the two sides is not the size of the loss but whether anybody lets themselves look at it.
A destructive quality can be built into an institution, then into manners, then into the atmosphere of a place, while a decent one has to be performed by a named person every time.
Cruelty can grow into a whole system that runs a world. Honesty has to be done by one person at a time.
Follow one destructive quality all the way out. It starts as a private belief about what people are like. Then it's how someone behaves. Then it's an organization that runs on it.
Then it becomes manners: a way of treating people so normal nobody sees it as cruel, because it feels like courtesy. Then a place that enforces it. Finally it's just the mood of that place, like the weather.
Now try the same thing with honesty and watch it stall. It gets as far as a movement, a small community, a practice under threat, and then it stops. Honesty never becomes the weather.
Fahrenheit 451 shows this at every size. A belief about what books do to people, then the firemen who burn them, then neighbors reporting each other, then a whole city built to hunt readers. Honesty survives only in hidden places and memorized pages, kept by a stubborn few.
So don't fix that imbalance. Build your story on it. If honesty in your story has an organization as big as cruelty's, you've taken away the cost of being decent, and your story goes with it.
When enough people make the same quiet compromise, it stops looking like a compromise. It starts to look like common sense, and then like good manners.
Check one thing in your draft. Does the force your protagonist is up against keep going without your antagonist? If it dies when your antagonist does, you wrote a win, not an argument.
Your antagonist's path costs them a specific human ability, and the difference between the two sides is not the size of the loss but whether anybody lets themselves look at it.
A sacrifice only lands when the story has already named what happens if nobody makes it.
Your protagonist and your antagonist begin inside the same destructive habit, and what separates them is that one keeps paying for the decent thing while the other found a way to stop.