Often, there is a brooding, mysterious character. This type of character may have a troubled past that colors their view of love, leading them to exhibit the darker aspects of love such as being overly controlling.
Often, there are young protagonists. Since the concept of innocence is closely related to youth, these young characters are at the center. They could be teenagers in a dystopian world who start off with an innocent view of how things should be but are quickly faced with the dark underbelly of their society.
Often, there might be a mother figure as well, even if she is not the main focus. She could play a role in either supporting or complicating the father - child relationship. For example, in some fanfics, she might encourage the father to be more involved with the kids.
Well, of course, the mother is a central character. She could be a strong - willed woman who has to face many difficulties in life while still showing great love for her child. For instance, she might be a single mother who has to work multiple jobs to support her family but still finds time to be there for her child's school events.
Typical characters in Dark Parables stories include the damsel in distress, although she's not always a helpless figure. She often has hidden strength. There are also the tricksters, characters who play with the rules and can be either helpful or a hindrance. And knights or protectors are common, those who are sworn to defend the good. They might be on a quest to save a kingdom or a person from the clutches of evil.
There are often brave adventurers. These are the ones who are not afraid to explore the areas around dark waters, whether it's a murky lake or a deep ocean bay.
The survivor is a typical character. This is someone who has managed to stay alive through the apocalypse and is constantly on the lookout for resources. There's also the villain, who might be a dictator - like figure trying to take over what's left. And the scientist, who may have some knowledge about what caused the apocalypse or how to stop it.
Since I don't know which 'the dark side novel' you're referring to, I can't tell for sure. But usually in a novel about the dark side, there might be a protagonist who is either fighting against the dark side or being lured into it. There could also be an antagonist who represents the dark side fully.
Often, an original female character created by the author is paired with Springtrap. This gives the writer a lot of freedom to shape the relationship. Another possibility is a brave and curious male character who is intrigued by Springtrap and falls in love with him.
There's often the 'dark ash' character who is at the center of the betrayal. There could also be a friend or ally who turns out to be the betrayer. Another typical character might be someone who stands by the 'dark ash' after the betrayal, perhaps a true friend or a love interest.
Typical characters in 'the secret agent dark novel' include the agents, of course. These agents are often loners, relying on their own wits and skills. There are also the handlers or bosses who give the agents their missions. And don't forget the double agents, who add an extra layer of mystery and danger as they play both sides.