Without having read the 'War of Secrets Novel', it's difficult to name the exact main characters. However, considering the nature of the title, there could be a diplomat - like character. This person would be in the middle of the war, trying to negotiate peace treaties while also being aware of and using various secrets. There might be a young hero or heroine, perhaps naive at first but quickly learning about the world of secrets as the war unfolds. And there could be an old, wise mentor figure who has knowledge of past secrets that are relevant to the current war situation.
In the Warhammer 40k War of Secrets novel, it's possible that there are main characters from different factions. There might be a tech - priest from the Adeptus Mechanicus who is trying to unlock some technological secrets. Or perhaps a Commissar who is involved in uncovering some political secrets within the Imperium. There could also be a Chaos cultist whose actions drive part of the story as the Imperium tries to root them out.
I'm not sure specifically as I haven't read the 'Temple Secrets Novel' in detail. But usually in such novels, there could be an adventurous protagonist, perhaps an archaeologist or a treasure hunter.
I'm not sure as I haven't read the book specifically. But typically in a novel about the secrets of flight, there could be an inventor or scientist type of character who is obsessed with understanding flight.
I don't know as I haven't read it.
I don't know the specific main characters as I haven't read the novel. But it could be a shrewd trader, a young and ambitious intern in a trading company, or a veteran broker.
There's no way to know without more information. However, in many graphic novels, the main characters are often ordinary people who get thrust into extraordinary situations involving secrets. So it could be a young person, maybe a student or an artist, who discovers something strange and is then drawn into a world of secrets. There may also be antagonists who are trying to keep the secrets buried and will stop at nothing to do so.
I'm not sure specifically as I haven't read the novel. But usually, in a novel about a city's secrets, there might be an inquisitive protagonist, perhaps a journalist or a detective type of character who is determined to uncover the secrets.
In 'Secrets of Cavendon A Novel', there might be a young protagonist, perhaps a daughter or a son of the family who is starting to uncover the secrets. There could also be an older, wiser character like a family butler or an aunt who has been around for a long time and knows a great deal about the family's past.
I don't know for sure as I haven't read the book. But it might have ranchers as main characters, given Wyoming's ranching background.
In many novels, there's often a group of main characters. In 'Secrets of Eden Novel', perhaps there's a young and curious character who takes on the role of the main investigator of the secrets. There could be an antagonist too, someone who wants to use the secrets for their own dark purposes. And there may be a sidekick or two, friends of the main character who support them in their journey.