I'm not sure specifically as I haven't read it in detail. But often in fanfics, there are characters from the original source that the fanfic is based on. So it could be the main characters from the 'x' that it's related to.
Maybe there are some underrated characters from the original 'x' who get more spotlight in this fanfic. They could be given more backstory and character development, making them the main focus in some parts of the story.
Since we don't know much about this 'the whispers the whispers' love story', it's impossible to say who the main characters are.
Sasuke might also be a main character. His complex personality and his relationship with Naruto could be explored in a new way in this fanfic. Maybe he's involved in some sort of mystery related to the screams and whispers, like he's the source of some of the whispers that Naruto is trying to understand.
Since I haven't read 'the whispers love story', I can't tell who the main characters are. But usually in a love story, there are two lovers at the center of the story. They might be from different backgrounds or have different personalities. In this 'the whispers love story', they could be two individuals whose lives are intertwined through the whispers, whether they are young or old, rich or poor.
I'm not entirely sure as I haven't read the specific 'Whispers of the Heart Novel'. But usually in novels like this, there's a protagonist, probably a young person, who is at the center of the story and drives the plot forward through their experiences and decisions.
I don't know the exact main characters since I haven't read the novel. But typically in a novel like this, there could be a curious explorer who discovers the house. There might also be an old caretaker who knows some of the house's secrets.
Without having read the 'Whispers in the Dark Novel', it's hard to say precisely. However, it's common in such novels to have a central character who is either a victim of the strange events or a seeker of truth. There might be a sidekick or a mentor figure to help this main character. There could also be an antagonist, someone who is causing or is related to the origin of these whispers, and is trying to keep the secrets hidden from the main characters.
Since it's called 'Whispers of Betrayal', there might be a character who is like a whisperer, someone who has some knowledge about the betrayal but is hesitant to come forward. This character could add an element of suspense to the story as the other characters try to figure out what they know and why they are being so secretive.
Since I don't know the exact story, I can't say for sure. But it could be two people who are in love, like a young man and a young woman.
Typically, in a 'Whispers in the Dark' gothic story, you'll find a female lead character. She could be a damsel in distress, perhaps a young heiress who has just inherited an old, haunted property. Then there's the brooding male character. He might be a mysterious stranger with a dark past of his own, and his presence adds to the sense of danger and intrigue. And don't forget the servants or caretakers of the spooky place. They usually know more than they let on and are often a source of important information.
The main characters are Anastasia and Alastor. We can assume that Anastasia is a character who will be affected by the betrayal. She could be a complex character with different layers to her personality. Alastor, he could be the one from whom the whispers of betrayal come. He may have his own motives and goals that are not clear at the start but as the story unfolds, we will learn more about him and his role in the situation of betrayal in relation to Anastasia.