I don't know for sure as I haven't read it. But I assume there would be the 'lady devil' herself as a main character. Maybe there's also a love interest who is either drawn to her or repelled by her devil - like nature.
Since it's called the 'lady devil novel', the main character is likely a female with some sort of devil - related aspect to her. There might be side characters like her friends or family members who either support her or are against her new - found 'devilish' identity. For instance, she might have a sister who is jealous of her powers or a friend who tries to protect her from the people who want to harm her because of what she is. There could also be a group of villains who are after her, making her life difficult and forcing her to constantly be on the run or fight back.
Since I don't know the specific 'lady in waiting novel', I can only guess. There would likely be the lady in waiting herself. Maybe there's a noble lady she serves, a love interest like a handsome nobleman or a dashing knight, and perhaps some other servants or court officials who play important roles in the story.
Not knowing the exact 'lady dragon novel', it's difficult to name the main characters precisely. However, in a general sense, the lady dragon would be a key character. There may be antagonists too, like an evil sorcerer who wants to use the lady dragon's power for his own dark purposes. There could also be a group of friends or comrades who support the lady dragon in her fight against evil or in her quest for self - discovery.
Without more information about the 'dark lady novel', it's difficult to name the main characters precisely. However, we can assume that the 'dark lady' is a central figure. She may be surrounded by a cast of characters that include friends or foes. There could be a wise old mentor - type character who tries to guide the 'dark lady' or a villain who wants to use her for his own purposes.
Well, often in such mystery novels, there's a central investigator figure. This could be a private detective or a police officer. Then there are likely to be characters related to the lady in the lake. It could be her friends, enemies, or family. There may also be some witnesses or locals who play important roles. They might provide key information or mislead the investigation, adding to the complexity of the story.
Well, clearly the lady and the unicorn are the main characters.
Since I'm not familiar with this particular novel, I can only guess. The main character would surely be the counterfeit lady. There may be a male lead who becomes involved with her, perhaps falling in love with her false self. And then there could be other supporting characters such as a nosy neighbor or a shrewd business partner who start to notice something strange about her and begin to dig deeper into her true identity.
The main characters would surely include the Lady of the Lake herself. And in an Arthurian context, King Arthur is likely to be a main character as his story is closely tied to the lady. Merlin, the great wizard, may also be a main character as he has connections with both Arthur and the Lady of the Lake.
There might be a human who gets involved with the devil. This person could be a curious soul who is lured by the devil's promises. For instance, a poor farmer who is desperate for a good harvest and makes a deal with the devil.
Typically, in a light novel like 'Beseech the Devil', there might be a central protagonist who is likely the one to have the most interaction with the devil - like element in the story. There could also be side characters such as friends or mentors who help or hinder the protagonist's journey. Maybe there is an antagonist who is either directly related to the devil or has a similar malevolent nature and is trying to stop the protagonist from achieving their goals.
The devil dinosaur itself is obviously a main character. It's likely to be big, strong, and a force to be reckoned with. There may also be a human character who befriends or has some sort of connection with the devil dinosaur.