Well, the obvious main character would be the colosseum king himself. He would be central to the plot, making decisions about the events in the colosseum. Besides him, there could be strong gladiators who are fan favorites and might have a role in the political or social aspects of the story. And there could be a character who is an opponent to the king, either politically or in the context of the colosseum events, like a rival noble who wants to take over the control of the colosseum and undermine the king.
I'm not sure specifically as 'coloseum king fanfic' could be about a wide range of things. It might be a fan - made story about a king in an arena - like colosseum setting. Maybe it involves battles, political intrigue, or the king's personal journey within that colosseum - centric world.
Obviously, Harry is a main character as the title suggests. There might also be his advisors, who could play important roles in guiding him as a king. And perhaps a rival king or noble who tries to undermine Harry.
There might also be characters like his advisors. They would play an important role in helping Brian make decisions and rule the kingdom. Their personalities could range from wise and old - school to young and innovative.
Obviously Naruto is one of the main characters since it's in the title 'naruto is king fanfic'. He is likely to be the central figure around which the story revolves.
I don't know for sure since it's a fanfic. It could be the dragon king himself as a main character. There might also be a brave knight or a wizard who has to deal with the dragon king or the things in his shadow.
Well, of course, the bard king himself is a main character. He is often depicted as a charismatic and talented leader. There's also likely to be his loyal sidekick, perhaps a jester or another musician who provides comic relief and support.
In the 'naruto the eternal king fanfic', Naruto is the central character. However, his friends from Team 7, including Sasuke and Sakura, are probably going to be main characters too. Additionally, characters from other villages such as Gaara from Sunagakure might be involved. They could be important in terms of international relations in the story where Naruto is the eternal king. Also, there might be new characters introduced who are specifically related to the concept of Naruto being an eternal king, like advisors or enemies who only exist because of his new status.
Naruto is surely one of the main characters. Since it's related to Naruto, he would be at the center of the story.
Nala could also be a main character. She's Simba's mate and is strong and independent. In the fanfic, she might be involved in protecting the pride or making important decisions for the future of the pride.
I don't know for sure, but it's likely the king himself is a main character. There could also be some advisors or nobles who play important roles, either supporting or opposing the king.