The SCP Secret Laboratory story has several main types of characters. First, there are the scientists within the SCP Foundation. These individuals are highly intelligent but often face moral and ethical dilemmas as they study and try to contain the SCPs. The security guards are also important characters. They are tasked with protecting the facility from SCP breakouts and external threats. Then there are the D - Class personnel, who are often used as test subjects. And of course, the various SCP entities which are unique in their own right and drive much of the action and danger within the story.
In the 'scp secret laboratory story', there are the members of the SCP Foundation, such as the scientists and security personnel. They play a major role as they are in charge of dealing with the SCPs. Also, there are the SCP entities themselves which, although not traditional characters in the sense, are central to the story. And then there are groups like the Chaos Insurgency who are antagonists and cause problems for the Foundation's operations.
The SCP Secret Laboratory story is centered around a strange and often disturbing world. It involves various SCP entities which are abnormal, often dangerous items, creatures or phenomena. The story usually takes place within a laboratory setting where researchers try to contain these SCPs, but things often go awry, leading to chaos and unpredictable events.
There are many entities that could be considered main characters. For example, the various SCPs like SCP - 173 and SCP - 096. These entities play a major role in the horror and mystery aspects of the story.
The main characters in the SCP game story are often the personnel of the SCP Foundation. They are scientists, guards, and agents who are tasked with containing the SCPs.
Typically, the main characters can be D - Class personnel, who are often used as expendable test subjects in the SCP Foundation. Another type could be the researchers who work in the Foundation.
As there is no information given about this story, it's impossible to say who the main characters are. They could be ordinary people with an extraordinary secret, or they could be fictional characters created for a specific plot.
Given the lack of context regarding the 'bastos secret secret story', we can only speculate about the main characters. If Bastos is a person, perhaps they are the central figure, and there could be friends, family members, or foes around them that are part of the story. Maybe there are also some mysterious figures that help or hinder Bastos in the discovery or protection of the secrets in the story.
In 'The Secret in Their Eyes Story', there could be a detective - like character as one of the main characters. This person would be observant and would focus on the eyes of suspects or other people involved in the mystery. There might also be a character who is the keeper of the most important secret. This character would be acting in a way to avoid having their secret discovered through their eyes. And perhaps there is a love interest as well, whose eyes hold a different kind of secret, like a hidden passion or a past relationship.
Since I don't know the details of 'the secret grave story', I can't say for sure who the main characters are. But they could be the people who discover the secret grave, like an archaeologist or a curious local.
The main character is a young hero. There is also a female character who becomes an important ally in the adventure. And there are some wise old men who guide the hero on his journey regarding the secrets of Mana.
Since I don't know the exact 'Secret of the Nile Story', I can't say for sure who the main characters are. But they could be explorers, local people living near the Nile, or maybe even some mythical creatures if it's a fictional and fantastical story.