Since I don't have specific knowledge about this novel, we can only make some educated guesses. There may be a protagonist who dons the black mask for some noble or not - so - noble reasons. There could be a sidekick or a love interest who helps or complicates the life of the black - mask - wearing character. And of course, there may be villains or authority figures who are in conflict with the main character.
Without reading the 'the black mask novel', it's difficult to determine the exact main characters. However, in a typical story with a black mask involved, there could be a masked hero or anti - hero. There might be a detective - like character trying to solve the mystery of the black mask. And there may be a group of characters associated with the masked one, either as allies or enemies, who play important roles in the story's development.
Well, it's hard to say for certain. But if we think about it, the main characters might include the victims of the Black Death. After all, they are the ones directly affected by the plague. And of course, the healers or doctors who tried to treat them and wore those masks. There could also be people in the community who had to deal with the aftermath of the disease, like those who had to bury the dead. These could all potentially be main characters in the story related to the 'Mask of the Black Death'.
The main character is Kotaro Minami, who is Mask Rider Black. And there are the villains from the Golgom organization.
There might be a group of characters. The one with the black mask is obvious. There could also be a detective - like character who is trying to solve the mystery of the black mask and the strange events happening. And perhaps a young girl who stumbles upon the black mask by accident and becomes a target of the horror.
In the 'Black Mask Hole Story', if it's a mystery - type story, the main character could be a detective - like figure who wears the black mask to hide their identity while they investigate the strange hole. There might be a local who has some knowledge about the hole and its secrets, and they could be another important character. And perhaps there is a shadowy figure in the background who is somehow connected to the hole and the black mask, either trying to protect its secrets or use it for their own malicious purposes.
Since I don't know the exact 'the black mask horror story', it could have a brave protagonist who is trying to uncover the mystery of the black mask. Maybe there's also an antagonist who is somehow related to the black mask, like the one who created it or is using it for evil purposes.
Besides Batman and Black Mask, there might be other characters like Commissioner Gordon. He could play a role in assisting Batman or providing information related to Black Mask's activities in Gotham.
Since we don't know the details of 'the mask novel', the main characters could be various. There could be a young adventurer who stumbles upon the mask and becomes the central figure in the story. There might also be a wise old mentor figure who helps the protagonist understand the true nature of the mask. And of course, there could be some side characters like friends or foes of the main character that play important roles in the plot as the story unfolds.
Maybe some criminals are also main characters in a sense. Their actions and attempts to evade the law create the conflict in the stories. For instance, a mastermind criminal who devises elaborate schemes that the detective has to figure out.
There are probably detectives as main characters, as it's a collection of crime stories. They might be tough and resourceful.
There are many main characters as it's a collection of stories. But often there are tough - as - nails detectives who are the central figures in each story, like Sam Spade - type characters.