One way to design realistic and complex enemies is to first imagine and design a good and moral character fighting for a noble cause. Then have that character take their approach to this problem to a malevolent extreme. Have your villain fight against a real injustice in your fictional world, have them stand against an oppressive regime, have them try to conquer death itself to save a loved one, but have them use terrible methods or seek vile solutions to their problem. Twist their fight from noble rebellion to sheer terrorism, let them lose empathy for those that they hurt along the way, have them believe their ends justify any terrible means. This approach to character-building not only quickly gives your evil nemesis more complexity, but also adds nuance and depth to any hero they may face, as now that hero will need to grapple with defending a system that is unjust and the source of harm.

A villain might assemble the outcasts of society, those treated unjustly by the world, and then form an army with them.

Loving and caring for another person (for most of us) is a powerful and relatable condition. Giving your evil mastermind (or malicious brute) a loved one they care for and letting them display this emotion can endear them to an audience. This other person may be a parent, a lover, a sibling, a child, or an important but unrelated role model. The addition of a loved one also creates opportunities to explore this relationship as well as the details of this new character. Often when this approach is used the loved one is morally ‘good’ and is used in an attempt to bring a villain back from the brink, however this doesn’t need to be the case. Having a pair of evil brothers or an evil father and evil son working together can also create interesting dynamics.

Frequently fictional villains will justify their actions to themselves, believing the evil things they do will give their family a better life.

Let your complex evil characters do good in the world. Have them be a powerful and transformational force for not only evil, but also occasionally good. Let them fund a local sports team, donate blood to the injured, or foster puppies. Of course, have a clear rationale for why they perform the actions they do, otherwise you risk generating purely chaotic and manic characters (which while interesting, may not be what you wish). If you want to encourage moral dilemmas in your fictional world, combine their good and evil acts. Have your character burn down the sacred forest to build a children’s hospital.

A tragic backstory is not just for your good guys, but can also help form the basis for an evil character. In fact a tragic backstory may be the reason why your evil character has a noble cause or may the reason why they do a good deed now and again. Reasons why evil characters act the way they do provides context for their actions. Of course, maybe your evil villain was just always that way…