There might be a fearless explorer. This character is always eager to push the boundaries and discover what lies beyond in the limbo. They are brave and not afraid of the unknown, leading the way for others.
Common themes could be exploration of unknown worlds. For example, in many science fiction novels, characters venture into uncharted territories in 'limbo' - like spaces, which could represent the vastness of the universe or the uncharted areas of the human mind.
Not having the details of the 'limbo graphic novel', it's difficult to name the main characters precisely. But in a general sense, it could have a character who represents hope. This character might be constantly looking for a way out of the limbo. There could also be a group of characters who are all in the same limbo situation, and they each have different personalities and reactions to this state. Some might be resigned to it, while others, like the hopeful character, are actively seeking a change.
Without reading the 'in limbo graphic novel', I can only speculate. It could have a young protagonist who has just entered this state of limbo, perhaps due to some unforeseen event. There might also be some secondary characters like friends or family members from the protagonist's past who appear in flashbacks or as memories in the limbo world. And there could be some mysterious figures that only exist in the limbo, and their purpose is to either test or torment the main character. The graphic novel may use these characters to build a complex web of relationships and stories within the overarching theme of limbo.
I don't know the main characters as I haven't read it. It could be a diverse group of people, perhaps some regulars at the Limbo Lounge.
Typically, Naruto would be a central figure. But it could also focus on characters like Sakura. She has her own strengths and development arc. In a limbo - related story, she might use her medical ninjutsu skills in unique ways in the limbo dimension. Also, Orochimaru could be a main character in some cases. His thirst for knowledge and power could lead him to explore the limbo, and Naruto may have to deal with him there.
There could be characters who are on a journey with the king in the limbo story. Maybe they are companions or followers who have their own stories and motives. And in the 'other stories', there could be different protagonists, each with their own unique personalities and goals.
I don't know who the author of the 'King of Limbo Novel' is. There are so many novels out there, and without more information, it's difficult to determine the author.
Harold Finch is one of the most interesting characters. He's the creator of the Machine. His complex past and his moral compass make him stand out. He has to grapple with the consequences of creating such a powerful tool. Another interesting character is John Reese. He's a former CIA agent with a lot of combat skills. His journey from being a broken man to finding a new purpose in protecting the numbers is engaging.
Kakashi can be a popular character in Naruto Limbo fanfiction too. His intelligence and combat skills can be put to the test in the strange and unpredictable Limbo. Also, characters like Itachi, with his strategic mind and powerful jutsu, can add depth to the stories set in Limbo. Their abilities can interact in unique ways with the properties of Limbo.
Since it's a fanfic, the main characters could vary widely. It might include some of the well - known Akatsuki members if the jail is somehow related to their activities. For instance, if the jail is a place where they keep their prisoners or secrets. Another possibility is that a new, powerful shinobi is introduced as the main character, who is on a quest to uncover the mysteries of the limbo border jail.