Since I haven't read the graphic novel, I can't say for sure. But usually in a story like this, there could be a brave hero or heroine. Maybe someone who is a scientist or an adventurer who is trying to figure out what the 'rings of fire' are all about.
In the 'Lord of the Rings Graphic Novel', Frodo Baggins is a central figure. He's a small hobbit from the Shire but has a great burden with the One Ring. Gandalf the Grey (and later Gandalf the White) is there to guide and protect. Aragorn, also known as Strider, is a key character. He's a ranger with a noble lineage and plays a crucial role in the fight against Sauron. Samwise Gamgee, Frodo's loyal friend, is also among the main characters, always by Frodo's side through the perils of the journey.
Miyamoto Musashi is likely to be one of the main characters as the original 'Book of Five Rings' was written by him. He was a famous Japanese swordsman.
One of the main characters is Hida Kisada. He is a powerful and complex figure, representing the Crab Clan. His strength and determination play a big role in the story.
Miyamoto Musashi is a main character as it's based on his teachings.
I don't know for sure, but there could be a brave hero who is trying to uncover the secrets of the throne of fire.
I don't know for sure as I haven't read it. But it could have a hero who has the power to control fire and is on a quest to save the world from an ice - based villain. Or maybe there are twin protagonists, one with an affinity for fire and the other for ice, and they have to learn to work together.
There are several important characters. Clay, the MudWing, is known for his loyalty to his friends. Tsunami, a SeaWing, is brave and often takes charge. Glory, a RainWing, is also a main character. She has unique abilities and a sassy personality. These characters play key roles in the various adventures and challenges in the story.
Since I haven't read it, I can't say for sure. But it could have characters like the homeowners, the firefighters, and maybe some neighbors.
In the 'Goblet of Fire Graphic Novel', of course, Harry Potter is a central figure. He has to face the dangerous Triwizard Tournament. His friends Ron Weasley and Hermione Granger play important roles. Ron has his moments of jealousy and then support for Harry. And Hermione uses her intelligence to help Harry figure out the mysteries around the tournament. Also, there are characters like Cedric Diggory, another Hogwarts champion, and the other school champions like Viktor Krum and Fleur Delacour.
I'm not entirely sure without reading it, but it might be the dragon characters that are central to the 'Wings of Fire' series in general.