Grover, Percy's best friend who is a satyr, could also be a main character. He often accompanies Percy on his adventures. In this fanfiction, he might be a key support for Percy in the game, perhaps using his skills as a satyr to help Percy overcome challenges within the game - like scenario.
Annabeth Chase is also likely to be a main character. She's Percy's girlfriend and a daughter of Athena. In the fanfiction, she might play an important role in helping Percy figure out the game he's in or be involved in the game herself in some way.
Since it's a Percy Jackson fanfic, Percy himself is likely to be one of the main characters. Annabeth might also be involved as she is often by Percy's side in the original series. Grover could be another main character too, depending on the plot of the fanfic.
One great 'Playing the Player Percy Jackson Fanfiction' story could be 'The New Game' where Percy is put in a situation where he has to outwit a new, mysterious player in the demigod world. It has interesting plot twists.
Piper could also be a potential love interest in this scenario. Given her charm - speaking abilities, she could either be a rival to Percy in the 'player' game or be someone he tries to charm. Their interactions would be filled with a mix of friendly banter and underlying romantic tension.
Obviously, Percy Jackson himself is a main character. He's the hero of the original series and in the fanfic, he's usually at the center of the action as a high school player. Annabeth Chase also often makes an appearance. She's Percy's friend and sometimes helps him out, whether it's with his schoolwork or dealing with the challenges that come with being a demigod athlete.
Obviously, Atlas is a main character. He's often portrayed in different ways, sometimes as a more sympathetic figure trying to break free from his past, or as a more menacing antagonist still holding onto his old grudges. Percy Jackson also often shows up. His interactions with Atlas can range from confrontational to reluctantly allying with him.
Obviously, Percy Jackson himself is usually a main character. He is the one who gets involved in the devil - related situations. And then there could be new characters created specifically for the fanfiction, like a devil - like antagonist who is trying to corrupt Percy or the world around him.
The main characters are, of course, Percy Jackson and Frank. Percy is the son of Poseidon, a brave and resourceful demigod. Frank is a son of Mars in the Roman aspect, with his own set of unique powers and a shy yet determined personality. They often interact in these fanfictions, either as friends, allies in a quest, or sometimes having to overcome differences.
In this fanfiction, Percy Jackson is the key character. However, there could be new characters introduced who are related to the pets. Maybe there's a pet owner who Percy teams up with. Or perhaps there are veterinarians in the demigod world who help Percy when the pets get sick or injured. And the pets themselves, which could range from a cute little mouse with a big secret to a majestic eagle that can fly faster than the wind, would be important main characters in the story.
There could also be new characters created specifically for the fanfiction. Maybe a new demigod who has some sort of power that is related to both Percy's water powers and Juniper's nature powers. This new character could bring a fresh dynamic to the story and be either a friend or a foe to Percy and Juniper as they navigate through the plot.
Percy Jackson is the central figure for sure. The dragon is another main character, whether it's a friendly or a menacing one. There could be new characters created specifically for the fanfiction. For example, a dragon tamer from an ancient demigod lineage who has knowledge about the dragon's kind. This character could either be an ally or an antagonist to Percy. And of course, we might see some of the minor gods or goddesses make an appearance, as they often have their own interests in the affairs of demigods and magical creatures like the dragon.