I'm not sure as I haven't read the novel, but they could be the spirit hunters themselves.
Well, since it's a spirit hunter novel, the main characters are likely to be the hunters. There might be a lead hunter who is highly skilled and experienced in dealing with spirits. There could also be some novice hunters who are learning the ropes. And perhaps there are some characters who have a special connection to the death mark, either they are marked themselves or they know something important about it.
In the 'spirit hunter death mark novel', it may center around characters who are spirit hunters. These hunters might have their own unique skills and tools for dealing with spirits. The 'death mark' in the title could play a crucial role in the plot. It could be a key element that drives the story forward, perhaps a mark that the hunters need to find and understand in order to stop some great evil related to the spirit realm. It could also be a mark that the spirits themselves fear or are attracted to, leading to all sorts of interesting interactions between the hunters and the spirits.
I'm not entirely sure about all the main characters specifically, but usually there is a protagonist who is the one directly affected by the death mark and has to find a way out of the situation.
The main character is surely the ghost hunter. But there could also be other characters like his sidekick if he has one, or the people who hire him to do the ghost hunting.
Well, of course, Zorro is the central figure. He's the one who is the masked hero. Then there's Don Diego Vega, his alter - ego. And there are the antagonists, which usually include greedy landowners, cruel military commanders, and other evildoers who are causing trouble in the region that Zorro is trying to protect. They all play important roles in the plot of the 'Mark of Zorro' novel.
I don't know for sure, but it might include characters related to Athena's world in Greek mythology. Maybe some demigods or heroes.
Typically in stories like the 'Mark of Athena Graphic Novel', the main characters could be descendants of the Greek gods. They would have unique powers and skills. For example, there might be a character like Percy Jackson, who has powers related to the sea god Poseidon. There could also be other characters with powers from different gods, and they would all come together for a common purpose, like saving the world from a great threat or fulfilling a prophecy.
Since I don't have the book in front of me, it's hard to say exactly. However, in a novel about a spirit house, there might be a protagonist who is drawn to the house for some reason, like a sense of curiosity or a personal need. There could also be other characters like a local guide who knows something about the history of the spirit house or a skeptic who doesn't believe in the spiritual aspect at first but then has a change of heart as the story progresses.
The main character is The Spirit, of course. He's the masked hero who drives the story forward with his investigations and battles.
The main characters in the 'river spirit novel' are likely to include the river spirit, which is probably the most important one. There might be a young adventurer as a main character too. This adventurer could be on a quest and by chance stumbles upon the river spirit. There could also be an old wise character, perhaps an elder from a nearby village who knows about the river spirit and its secrets. They could guide the younger characters in the story. And if the novel has a more complex plot, there could be some sort of a shadowy figure or a group that is after the power of the river spirit and they would also be main characters in the conflict that unfolds in the story.
Since I haven't read it, I can't say for sure. But there's probably a spirit walker as a main character. There might also be a mentor figure who helps the spirit walker understand their powers better.