In most novels with the title 'Caught by the Villain', the main character is the person who falls into the clutches of the villain. This character is usually the focus of the story, and we see the events unfold from their perspective. The villain is also a central character, driving the conflict. There may also be a supporting character like a family member of the protagonist who is trying to rescue them, or a detective - like character who is on the trail of the villain and the missing protagonist.
Since I don't have the details of this particular 'Caught by the Villain' novel, generally speaking, the main character is the one who is caught, let's call them the hero. The villain is another main character. There could be other important characters like a mentor figure who might have given the hero some skills or knowledge before they got caught, or a fellow captive who teams up with the hero to escape from the villain.
I don't know as I haven't read the novel. It could be a male protagonist who is the central figure in the story.
I recommend " The Villain's Me Caught by Them ". The author is lacking in virtue and talent. This light novel described how the protagonist, Chen Mo, had transmigrated to another world and was bound to the strongest villain system, offending all the female protagonists. In a desperate situation, he had bound himself to the love-hate system. This novel was in line with the plot in question. The female protagonist captured the villain.
There were a few novels about villains who had been caught by the main characters that could be recommended, including When the Villain Was Caught by the Protagonists, The Black Lotus Female Supporting Character's Horse Catching Manual [Wear It Quickly], and As the Villain, I Captured the Female Lead, Is It Good? and the Villain Growth System. These novels all involved the protagonist catching the villain. I hope these recommendations will meet your needs.
In some 'caught short stories', the main character could be an adventurer. Let's say in a story about being caught short of supplies during a jungle exploration. This adventurer has to face all kinds of challenges without the proper equipment. They are the focus of the story as they struggle and find ways to survive.
I don't have enough information to tell who the main characters are in 'caught in the heartbeat fanfic' as I haven't read it. It could be characters from the original work that the fanfic is based on.
I don't know for sure as I haven't read the 'villain days novel'. But I would assume there would be at least one main villain character. There could also be characters who oppose the villain, like heroes or other characters caught in the middle of the villain's actions.
Since I haven't read it, I can't say for sure. But typically, there would be a protagonist who is the one aiming to kill the villains. There might also be sidekicks or allies that help the main character in their quest.
As I don't know the specific 'Caught 2015' work, it's difficult to say who the main characters are. But if it's about a crime, the main characters could be the criminal, the detective or police officer who caught them.
Obviously, the main characters are the boy and his grandmother.
I don't know for sure as I haven't read it. But in 'Twilight' - related fanfiction, it's likely that Bella, Edward, and Jacob could be main characters. They are the central figures in the original 'Twilight' series, so it's very possible they play important roles in this fanfiction as well.