Not having read 'the black ghosts short story', it's impossible to name the main characters accurately. However, in a story about black ghosts, there might be a curious investigator type of character who is determined to understand the black ghosts. There could also be a victim - someone who has been directly affected by the black ghosts in a negative way. And perhaps there's a wise old character who has some knowledge about the black ghosts and provides guidance to the other characters.
As I don't know the specific 'the ghosts short story', it's hard to say. But it could be a person who stumbles upon the ghosts, like a curious journalist or a new resident in a spooky place.
The main characters are often the ones who encounter the ghosts. It could be a curious journalist who goes to a haunted location to write a story. They are usually brave enough to face the unknown and dig deeper into the mystery of the ghost.
As I don't have access to the 'the black ghosts short story', I can only guess at the main theme. It might be centered around the black ghosts as symbols. For example, they could symbolize the dark side of human nature or some hidden danger in the story's setting. Or perhaps it's about the search for the truth behind these black ghosts, which could imply a theme of discovery and revelation.
There could be characters like a young girl who has the ability to see ghosts from a young age. In the stories, she might be on a journey to understand why she can see them and how to interact with them. Another type of main character could be an old man who has lived in a haunted place all his life and has many stories to tell about his experiences with the ghosts there. These characters would bring different perspectives on living with ghosts to the stories.
I'm not entirely sure as the specific details of the 'The Black Telephone' short story are not fully known to me. But typically in such stories, there could be a protagonist who is the main character affected by the black telephone. There might also be some secondary characters like a family member or a neighbor who either helps or hinders the protagonist in dealing with the situation related to the phone.
The boy who is abducted is the primary character. He is in a fight for his life and sanity. The kidnapper is another key character. He is the source of all the fear and danger in the story. While we may not know much about the kidnapper's backstory, his actions and the threat he poses to the boy are what shape the story. There could also potentially be family members of the boy that are indirectly part of the story through the boy's thoughts and memories.
Perhaps a group of rebels. They might be fighting against an oppressive force that rules the black city, adding an element of conflict to the story.
I'm not sure as the details are not given, but it could be a person who encounters the black dog.
I don't know for sure as I haven't read the story. It could be an explorer who is interested in the black orchis.
I don't know since I haven't read the story, but it could be a child who discovers the black phone.