Now, here’s a real gem for you to remember. “Your villain must be special for your novel to work.” If the villain is a bumbling idiot or a flaming activist, what challenge is he for your hero/heroine? Create a savvy, sneaky, dangerous, scheming, shrewd, cool, smooth, stylish, villain with a personality that borders condescending sarcasm or some other flaw(s). No character; villain, hero, or heroine should be perfect, unless your character ‘believes’ he is . . . which is completely different than flawed.
The more charming, clever, likable, and even loving your villain is - the more invincible he is and the harder your protagonist must work to bring him/her to justice. The villain may be loathsome and even evil inside, but he’s harder to catch if it’s hidden. The protagonist(s) must find or understand the villain’s vulnerability. Not easy if he’s cunning and clever.
Bear in mind, if you create a villain that’s real, complex, and likable, the reader can empathize with the villain and his crimes can be somewhat justified. You must make sure you reveal what motivates the villain to kill so we believe his actions.
In Atonement my reader is inside the killer’s head. You see his perspective every step of the way. There's no doubt why he kills . . . and the reasons for the way he kills. The reader can’t help but understand . . . and even feel a tinge of empathy for him.
Villains develop for varying reasons. He might want to right a wrong. We all know revenge is a serious drive for killing. Maybe the villain believes the law isn’t doing its job and he feels a need for vigilante justice. Of course we all can empathize with the villain who is protecting his loved one. Last, there are villains who feel he must reset world order.
It’s so important to make sure your reader understands - Why is the villain the way he is? Was he deserted at birth, misused as a child, neglected, blamed for sibling’s inadequacies, or over-weight and was ridiculed by classmates, or maybe no one would be his friend . . . the reality that has molded your villain is imperative to share. In understanding how the villain justifies his crime(s) to himself will expose what in his life triggered his crime(s).
I’ve read that you should paint your villain in shades of gray. I don’t know who said it, but I love that! It’s exactly what we should remember to do.
One last thing to consider about your villain – would he really commit the crime? I know that sounds strange, but think about it. Whether he stabbed, poisoned, strangled, or even buried his victim alive – would he have done that?
Say your villain is the chubby guy who has always been ridiculed. He wouldn’t likely bring his victims to a rocky quarry eight hundred feet up a rocky ledge, would he? Would your small, gentle, beloved preacher get drunk and shoot a parishioner with a forty-five magnum? Can he handle a forty-five and would he atypically get drunk? What if your killer is a bomber? What gives him the expertise to be such a killer? It’s so far ‘out-of-character’ – then it’s not believable. The villain’s conduct must fit the crime. His motivation must fit the crime. The amount of rage must fit the crime.
Now bear in mind – not only must you think about what crime your villain would commit, but also ask - Would other characters in the story feasibly commit the same crime? We are trying to be discreet, give our reader options, and even surprise them when the killer is revealed.