Sebastian Michaelis is also a key character. He is a demon who has made a contract with Ciel. He is extremely capable, with skills in combat, etiquette, and many other areas. He serves Ciel in exchange for his soul once Ciel's revenge is complete.
Since I don't know the exact details of this story, it's hard to say for sure. But if it's related to 'Black Clover', it could feature Asta, Yuno, and their friends. They are the main characters in the original 'Black Clover' series, so it's likely they would be involved in this black beach story as well.
Not having read 'the black farm story', it's hard to determine the main characters. However, they could potentially include a strong - willed black female farmer who is breaking gender and racial barriers in the farming world. Her children might also be main characters as they grow up on the farm and face different challenges. Additionally, there could be a local advocate who fights for the rights and success of the black farm in the face of external pressures like big corporations trying to buy the land.
I'm sorry, I don't know as I haven't read the 'Black Monday Novel'. There could be businessmen if it's related to a financial Black Monday, or just ordinary people trying to survive a difficult day.
I don't know for sure, but if it's about black eagles in nature, the main characters could be the eagles themselves. Maybe a male and a female eagle that are building a nest and raising their young.
Since I don't know the specific 'the black coffin story', it's hard to say. It could be the person in the coffin, or the people who discover the coffin.
Not having read the 'Beyond Black' novel, it's difficult to say exactly who the main characters are. However, in a story that seems to deal with the concept of 'beyond' and 'black' (which might imply mystery or the supernatural), we might expect to find a character who is haunted by something from the other side. This character could be a young person, perhaps in their twenties or thirties, who is trying to make sense of their experiences. There might also be a sidekick - type character, someone who is more practical and tries to ground the haunted character. And then there could be an antagonist of sorts, a force or entity from the 'beyond' that is causing trouble or standing in the way of the protagonist's journey towards understanding or peace.
I'm not sure specifically as I haven't read the 'black ice novel'. But generally, the main characters are often the ones driving the plot forward, facing the major conflicts and challenges in the story.
There might be a group of characters. For example, a young protagonist with special abilities and his or her companions. They could be from different backgrounds and bring different perspectives to the story. There could also be an antagonist, perhaps a powerful being that opposes the main characters and creates conflict.