I don't know specifically which 'leviathan novel' you're referring to. There could be many novels with that name or a related title, each having different authors.
Leviathan in DC Comics is a secretive and enigmatic entity. It has ties to various heroes and villains, manipulating events from behind the scenes. Its true motives and leaders are often shrouded in mystery.
Leviathan in DC Comics is a shadowy force that operates behind the scenes, influencing events and challenging heroes. Its members and motives remain largely hidden, adding an air of mystery and intrigue.
I'm not sure specifically as I haven't read this particular 'leviathan full novel'. But generally, in a novel with such a title, the main characters could be those who interact with the leviathan - like concept. It might be a hero who tries to confront it, or a group of people affected by its presence.
Not having read the 'leviathan graphic novel', we can only guess at the main characters. It's possible that there's a young protagonist who stumbles upon the mystery of the leviathan. This character could be an outcast or someone with a unique perspective. There might also be an older, wiser figure like a mentor who helps the protagonist understand the nature of the leviathan. Additionally, there could be a group of characters, perhaps friends or comrades of the protagonist, who join in the adventure or the struggle related to the leviathan. Their different personalities and skills would add depth to the story and how they interact with the main threat or mystery that the leviathan represents.
Since I haven't read it, I can't say for sure who the main characters are. They could be young heroes on a quest, or perhaps scholars researching the leviathan.
There's Jim Holden. He's a key character, very much an idealist who gets caught up in a web of interplanetary intrigue. And then there's Miller, a detective with his own set of problems and a rather jaded view of the world.
The main character is Percy Jackson. He has his own set of powers and a destiny to fulfill. Alongside him, we often see characters like Nico di Angelo. Nico's dark powers and his knowledge of the underworld can be a great asset in the battle against the Leviathan. Also, there could be some sea - related deities or creatures that become important characters in the fanfiction, as the Leviathan is a sea monster. They might either help or hinder Percy's quest.