Since I don't know the specific 'death watch novel', I can't say for sure. But they could be the people on the death watch, like a doctor, a family member, or a professional caregiver.
I'm not sure specifically as I haven't read the 'death notice novel' in detail. But usually in such novels, there is a protagonist who is likely to be someone involved in solving the mystery or facing the challenges related to the 'death notice'.
The main characters could include the god of death, of course. There might be a human character who has a special connection to the god of death, perhaps a seer or someone with a rare gift. And there could be a council of deities that the god of death has to interact with, whether they are allies or foes. These various characters would each contribute to the overall plot and theme of the novel.
Since I'm not familiar with the book, it's hard to say who the main characters are. But they could be humans who are involved in the robotics industry, like engineers or scientists. Or perhaps there are some special robots that are the focus, such as a robot detective or a powerful combat robot.
Since I don't know the specific 'death crone novel', I can't say for sure. But likely, the death crone herself would be a main character. There might also be characters whose lives she affects, like a young hero who tries to stop her evil deeds if she's a villain, or a person seeking her wisdom if she has a more ambiguous role.
The main character is Gustav von Aschenbach, an aging writer. And then there's Tadzio, the beautiful young boy who becomes the object of Aschenbach's obsession.
I'm not entirely sure about all the main characters in the 'death stranding novel' since I haven't read it fully. But based on the game, in addition to Sam, characters like Mama, who has a special connection to a BT, could be important in the novel. There may also be new characters introduced in the novel that play crucial roles in the story, perhaps some leaders of the different settlements or people who have special abilities related to the chiral network.
I don't know specifically as I haven't read it, but there's likely to be the adept themselves (even though they die), and perhaps people close to the adept like friends, family, or colleagues.
The main characters in 'the death of superman novel' include Superman himself. Then there's Lois Lane, who has a deep connection with Superman. Also, other characters like Jimmy Olsen from the Daily Planet might be important. And, of course, the villains such as Doomsday who is probably the one responsible for Superman's death.
There could be a protagonist who is deeply affected by the death of the fox. This character might be on a journey of discovery, trying to understand the significance of the fox's death. Maybe there is also an antagonist, someone or something that caused the death of the fox, whether it be a natural force or a malevolent entity in the story.
I'm not sure as I haven't read the novel. But it could have a detective as a main character if it's a crime or mystery story. Maybe a victim or a relative of the victim who is trying to seek justice.