One character could be Dumbledore. Although he is seen as a great and wise figure, in some fanfiction scenarios, his complex plans and secrets could lead to a situation where Hermione feels betrayed. For instance, if his plans involve sacrificing Hermione's well - being for the 'greater good' without her knowledge.
Ron is a likely candidate. In the original story, they had their ups and downs, and in fanfiction, it's easy to imagine him doing something that Hermione would see as a betrayal, like not supporting her in her academic pursuits. Another could be Draco Malfoy. He could pretend to befriend her for some devious reason and then turn on her.
Perhaps there is some sort of political intrigue within the 'light side'. There could be factions that see Hermione as a threat to their own power and influence. So, in order to maintain their position, they choose to betray her.
Some fanfictions might have Misty betray Ash. Perhaps she gets lured by the promise of power or some valuable reward. She could be tricked into believing that Ash is no longer the friend she thought he was and that betraying him is for the greater good.
One character that could betray Percy is Thalia. She has her own issues with the gods and her place in the world. Maybe she gets jealous of Percy's growing popularity and power among the demigods. So, she decides to side with an enemy to take Percy down a notch. Additionally, some minor characters that Percy has helped in the past could be the ones to betray him. They might feel indebted to him but also resentful at the same time. An enemy could manipulate their feelings and turn them into traitors against Percy.
Ares could be a likely character. He's always been somewhat of a wild card in the Percy Jackson series. He might betray Percy for his own amusement or to gain more influence in Olympus. Another could be Zeus. He's often paranoid about his power and might see Percy as a threat and betray him to protect his throne.
Obviously, Harry Potter himself would be one of the main characters. Since the title implies his betrayal by the light, he is the central figure through which the story unfolds. Hermione and Ron could also be important characters as they are Harry's closest friends. Their reactions to Harry's situation and whether they side with him or the light side that is betraying him can add a lot of drama to the story.
Yes, it could be. It might suggest that side characters are not considered important enough to have their own light novels. This view may limit the potential exploration of side characters' backstories and development in the light novel genre.
Even Hinata could potentially be written as a betrayer in some really out - there fanfictions. Maybe in a crossover where there are mind - control elements, Hinata could be forced to turn against Naruto. But this would be a very different take on her character as she's usually portrayed as extremely loyal to Naruto.
Even Ginny could be written as a betrayer in a fanfic. For example, if she becomes possessed by a dark force, she might turn against Harry. Her relationship with Harry is so central in the original story that a betrayal from her would be a huge shock and create a lot of drama in the fanfic.
It depends on the specific plot of the fanfiction. It could be a friend who turns against her due to jealousy, or perhaps a false ally within the so - called 'light' side who has ulterior motives.