For anyone who attended Catholic school run by angry nuns, they know what it’s like to have harsh teachers forcing lessons down your throat using fear and outright pain to make you learn. That’s a great image to remember when you visualize your villain.
In every story, your hero needs to change to become a better person and achieve a goal. However, the hero needs help from a Mentor who gently teaches the hero a lesson, which is your story’s theme. Of course, people don’t always learn through kindness, so that’s where your villain comes into play.
On the simplest level, your villain exists solely to provide conflict. This is on the level of bad martial arts movies where the hero and the villain endlessly fight for no apparent reason. To move your villain beyond just mindless fighting, you need to make your villain a harsh teacher of your story’s theme.
While your Mentor teaches your hero to change through kindness, your villain inadvertently teaches your hero to change through viciousness. In “Star Wars,” Darth Vader forces Luke to go with Obiwan after the stormtroopers wipe out Luke’s aunt and uncle. Darth Vader’s capture of Princess Leia provides Luke with a reason to rescue her and discover his courage. Darth Vader’s Death Star approaching the rebel base allows Luke to wipe it out and save the galaxy, thereby fulfilling Luke’s dream of an adventure.
In a twisted, demented way, Darth Vader teaches Luke to grow and change. Of course, Darth Vader or any villain isn’t doing this deliberately, but when you’re creating your own villain for your story, make your villain not only fight your hero, but indirectly force him or her to change into a better person. Then your villain provides the final test allowing your hero to achieve his or her emotional goal by defeating the villain.
Your villain is critical to your hero’s growth. Without a villain, your hero has no reason to change and no way to change. With the right villain, your hero has to change by fighting the villain.
So your hero changes over time through the loving help of a Mentor and the vicious temper of the villain. This represents the carrot and the stick approach to teaching the hero to change into a better person. As long as the villain keeps inadvertently forcing your hero to change, you have the right villain.