For 'The Shadow over Innsmouth', the protagonist is Robert Ogilvy, who travels to Innsmouth and gradually uncovers the town's connection to the Deep Ones and the overarching Cthulhu Mythos. His journey is one of discovery and horror as he realizes the extent of the town's corruption and the influence of these otherworldly entities.
In 'At the Mountains of Madness', the main characters are members of the Antarctic expedition, like William Dyer. They are the ones who encounter the Elder Things and have to deal with the implications of their discovery in relation to the Cthulhu Mythos. They are faced with terrifying and mind - bending situations as they try to make sense of what they've found.
Often there are investigators. They are usually the ones who stumble upon the dark secrets related to Cthulhu. For example, a detective or a scholar.
There might be cultists as well. These are the followers of the Cthulhu - related entities. They are usually depicted as being fanatical in their beliefs and willing to do whatever it takes to serve their dark masters. They can be quite menacing as they try to carry out their rituals or stop the investigators from interfering.
The main characters in the Cthulhu original story include Randolph Carter. He's sort of the human connection in the story, a character through which we experience the strange and terrifying world of Cthulhu. And of course, Cthulhu, the massive, tentacled, and otherworldly entity that sleeps in the sunken city of R'lyeh. There are also other minor characters who help to set the scene and add to the overall atmosphere of the story.
One of the main characters is the narrator, who starts to uncover the mystery of Cthulhu. There's also Professor Angell, whose research sets the story in motion.
There's often the investigator character who is trying to uncover the secrets of the Cthulhu mythos. Also, there are the cultists who worship the ancient and terrifying entities.
I don't know for sure since I haven't read the novel. But typically in Cthulhu - related stories, there might be a brave adventurer or a scholar who gets drawn into the chaos.
I'm not sure specifically as I haven't read it, but likely there are investigators. These could be people with different backgrounds like a detective, a scholar, or a journalist, all drawn into the mystery of the Cthulhu Mythos.
Perhaps there's a detective - like figure who is called in to investigate the strange happenings in the asylum. And on the other side, there could be some sort of cultist figure among the inmates or staff who is trying to bring about the full emergence of the Cthulhu - related horror. Another possible main character could be a survivor of a previous encounter with Cthulhu - like forces who now finds themselves in the asylum.
There could be other characters like cultists who play important roles in the 'Call of Cthulhu 2018 game story'. The cultists are usually the antagonists, trying to bring about the rise of Cthulhu. And there might be some locals in the game world who either help or hinder the investigator with their knowledge or actions.
Often, there are investigators. They are the ones who start to dig into the strange happenings related to Cthulhu. For example, a detective who notices a series of disappearances that seem to be linked to something far more sinister than normal crime.