There's no way to be certain without reading the 'gate house novel'. However, it might feature a caretaker of the gate house who has been there for years and knows all the ins and outs of the place. There could also be a group of children who play around the gate house and discover something extraordinary about it, and they could be among the main characters in the story.
Since we don't have much information about this novel, the main characters could be various. It could be an old hermit who has made the gate house his home and a young traveler who stumbles upon the gate house and their interactions form the crux of the story. Or perhaps it's a family who has recently moved into the gate house and they are dealing with the strange new environment and the local community.
I don't know as I haven't read it. But they could be the people who live in the gate house, like a gatekeeper or his family.
Since I'm not familiar with the 'Traitors Gate Novel', it's difficult to name the main characters. However, considering the title, we can assume that there might be a character who is wrongly accused of being a traitor and has to fight to clear their name. There could be an antagonist who is trying to frame others and use the traitors gate as a means to an end. There may also be a wise old character who knows the secrets of the traitors gate and helps the protagonist in their journey. There could be other supporting characters like friends or family members of the main characters who play important roles in the story.
Since I don't know the specific 'light gate novel', I can't tell who the main characters are.
I'm not entirely sure who the main characters are without reading it specifically, but they could be adventurers like a brave paladin or a cunning thief.
The main character is Shin. He is a powerful player in the game - turned - real - world.
Yoji Itami is a main character. He is a soldier who gets involved in the events related to the gate. His character is interesting as he has to adapt to the new and strange situations in the fantasy world.
I don't know the specific main characters as I'm not familiar with a particular 'Star Gate' novel. It could be a group of scientists, explorers, or soldiers.
The main character is Okabe Rintaro. He is the one who drives much of the action regarding the time - travel experiments. Another important character is Makise Kurisu, a brilliant scientist who gets involved in the whole time - travel mess.
I'm not entirely sure as I haven't fully read it, but usually in such novels there is a protagonist who is at the center of the story. Maybe there's also a mentor - like figure who guides the protagonist on his journey.
One of the main characters is Gorion. He plays a crucial role in the beginning of the story. Another is the protagonist whose journey we follow throughout the novel.
Since I haven't had the chance to read the 'orient gate graphic novel', I can't say for sure. However, it's common for graphic novels to have a protagonist who is on a journey. Maybe there's a young person who discovers the orient gate and becomes the central character. There might also be a mentor figure or an antagonist who tries to stop the main character from achieving their goals related to the gate.