There are also his comrades like Ben Edwards who are important characters. They are part of the military unit with Reece and their relationships and fates are intertwined with the overall story. And then there are the antagonists, who are often involved in the conspiracy that Reece is trying to expose. Their actions create the obstacles for Reece to overcome.
Another significant character could be Katie Buranek. She has her own role in the story, often getting involved in Reece's quest for truth. Her relationship with Reece adds an extra layer of complexity to the story. There are also various military superiors and colleagues that play important roles in different parts of the novels, each contributing to the complex web of relationships and events.
The main character is James Reece. He is a Navy SEAL and the central figure around whom the story revolves. His actions and decisions drive the plot forward.