Rules for Writers- Number Fourteen
Good does not mean Nice; Evil does not mean Cruel
It is perfectly possible for a technically good person to be mean. In fact it might be good for you to try and write a character that does good things, but also manages to come across as at least cold-hearted. Remember that the person who claims to be righteous can be dangerous; very few villains will say they are evil.
I played a Dungeons & Dragons game a few years ago. We wanted to make things a little more interesting, so we drew straws for our character classes and spent the session working on their sheets. As you can probably guess I drew the Paladin; I knew I wanted this Paladin to be different. So I went do the route of making someone who could have been villain.
It was surprisingly easy. A paladin will lose their powers if they disobey the rules; this includes doing too many evil deeds and hanging out with those who do. How they respond to other people doesn't come into the equation, so long as they aren't actively trying to hurt an innocent person. And I pushed the line a bit; I managed to reason how something bad could be counted as good.
Example, well I killed someone who didn't do anything to me. My party were roped into saving a kidnapped person; we defeated the kidnappers and one of them surrendered. I opted to go by the 'no prisoners' plan and do away with him. My reasoning was that he would be hanged anyway, and this ensured he didn't get a chance to run away. I was cutting out the middle-man.
As you can tell my paladin was a well-intentioned extremist. He was zealous in his belief of right and wrong, which blinded him to his own behaviour. He treated others with respect; however he was very critical of those around him. It got to the point where there was an In-Character conflict between him and a ranger.
The campaign went well, but the paladin did manage to cause in-game trouble. He also reaped what he sowed and all was good. The reason this worked is because created a lot of flawed yet good intentions, with a little bit of self-righteousness. Just because a person does something good doesn't make them a good person.
Evil works in the same way. There are perfectly decent human beings who do terribly things, just look at the Stanford Prison Experiment. Someone can be the embodiment of kindness and still do shitty things; I have an example of this as well. I watched an anime called Noir a while ago and I remember the character Altena.
She came across as loving and kind-hearted, to the point of being motherly. Yet in the end her intentions were to create Noir; a pair of assassins who hated the world. She wanted assassins who would seek out evil and destroy it. Thus she engineered a series of events, and manipulated someone who cared about her. She had a good idea of who would die in the end.
Altena was a villain, but she had her reasons and…well there were understandable. I wouldn't say they justified her actions; I understood why she did what she did. Alongside all this she was a nice person. If I met her without any knowledge of her previous actions, I'd probably think she was a saint.
But none of this excuses her actions. At the end of the day I have to call her a villain; she pitted three people against each other. She believed with all her heart that one of them had to die, and remaining two had to hate. They had to hate themselves and they had to hate the world. And in the end she in fact planned on killing herself in order to cause this hate, she planned that far.
A writer who can separate good and evil from kind and cruel is a good one. And all you have to do is ask one question, what sort of person willingly calls themselves evil?