I've been thinking a lot about character development lately. I've been watching a few different TV shows that incorporate negative growth -- where a good person makes bad decisions, and does things that could be considered "evil."
My own main character starts off in my WIP as a relatively neutral character--she has her own personal biases and preferences that could be categorized as "good". But as the story progresses, she becomes less and less inclined to remain that way. There are events that drive her to a point where she makes decisions she can never undo, and performs atrocities that she will never recover from.
I've found that I actually love sudden insurgence of this type of character development in popular media. I even have a few examples that people may be familiar with.
In season 2 of AOS, we see Simmons struggle with the knowledge of what she did to Bakshi and the guilt she holds--though it stems more from having to lie and keep that to herself than it is from the action itself. She has crossed a line that, as a doctor and a woman dedicated to protecting people, she never truly expected that she would want to cross.
Or perhaps Clarke Griffin from THE 100, a idealistic and merciful girl forced into a situation that requires making difficult choices that often result in the deaths of innocent people, rapidly escalating in consequences -- eventually she makes a decision so horrifying in its calculation that she cannot bear to remain with her own people.
Willow Rosenberg of our beloved BUFFY THE VAMPIRE SLAYER, the lesbian witch whose lady love was murdered instead of the Slayer, which sent the redhead on a vengeful killing spree high on magic. She goes so far as to fight her own friends -- tense scenes of Willow vs Buffy that still kind of breaks my heart, and Giles, pulling an unexpected powerhouse punch. Xander, with his heartfelt speech that drags Willow from the edge of destroying the entire world.
Though Willow surely comes back from being evil, and redeems herself, she can never erase the things she did when she was evil. It's established in later seasons that she not only still struggles with an addiction to magic, but also has a lot of issues stemming from that loss of control. Though it was triggered by an awful grief over the death of Tara, she still skinned a man alive. You don't just bounce back from that.
I have a lot of feelings about characters that are forced to make that first choice that leads them down a dark path that they can never truly return from.
I find that negative character development like these examples add elements of realism to the fantastical stories that they are. Aliens, post-apocalyptic sci-fi, superheroes, vampires & witches...oh my. The decisions that these characters have to live with, the lives they've taken, and the consequences of that.
And I sincerely hope that with my own work in progress, that same sense is coming across for my characters.