Without reading the fanfic, it's impossible to know the main characters. However, based on the title, they could be characters who are either creators or exploiters of chaos. Maybe there's a cunning anti - hero type who sees chaos as an opportunity and is the central figure in the story, or it could be a group of characters who together form a sort of chaotic alliance to climb the metaphorical ladder.
There's no way to determine the main characters in 'chaos is a ladder fanfic' without actually reading it. But one can make some educated guesses. It might feature a protagonist who is a master of chaos, someone who can manipulate and use it to their advantage. There could also be secondary characters who either oppose this character's use of chaos or are caught up in the chaos created by the main character. For instance, there could be a wise old mentor - like figure who tries to guide the chaos - loving protagonist away from the dangerous path of using chaos as a ladder, or there could be a group of innocent bystanders who are affected by the chaos that the main character is creating in their pursuit of climbing the 'ladder'.
I'm not sure specifically what that particular 'chaos is a ladder fanfic' is about without reading it. It could be a fan - created story based on the concept of 'chaos is a ladder' which might involve themes of using chaos to climb or gain power, like in some fictional or game - related scenarios.
I don't know for sure as I haven't read it, but it's likely to include some of the well - known 'Harry Potter' characters like Harry, Hermione, and Ron. Maybe it also has some original characters created specifically for this fanfic who interact with the main trio around the mystery of the ladder.
Naruto would likely still be one of the main characters. Since it's a Naruto - related fanfic, he's bound to play a central role, probably with his new chaos - influenced abilities or situation.
In this fanfic, Chaos is surely one of the main characters. As for the others, it could include Athena, the goddess of wisdom. She might play a crucial role in devising plans to cooperate with Chaos to save Olympus. There could also be a centaur or a nymph that has some special knowledge or ability that aids in the whole process. Another possible main character could be Apollo, with his powers of light and prophecy being useful in the fight against the threats to Olympus.
The main characters in a 'naruto heir of chaos fanfic' might be the heir of chaos, of course. They could be a young ninja with a troubled past, perhaps an orphan who discovers their unique heritage. Naruto would likely be involved too. Maybe there are also some other well - known Naruto characters like Sasuke or Sakura. Sasuke could be suspicious of the heir of chaos and see them as a threat to his own goals, while Sakura might try to understand the heir's motives and help them fit into the ninja world if she believes they are not truly malicious.
Obviously, Percy Jackson is one of the main characters. He is usually at the center of the action. Another common character is Annabeth Chase. Her relationship with Percy often plays a role in the fanfic. Chaos itself can also be considered a main character in a sense, as it is the driving force behind many of the events.
There could be a human scientist as the main character. This scientist is researching the Chaos Emerald Z and accidentally activates some of its powers. Now, they have to deal with the consequences, like strange creatures emerging from other dimensions due to the emerald's energy. They would have to use their scientific knowledge along with the help of some new - found friends to control the situation.
Obviously, Harry Potter is the main character as he is the Son of Chaos in this fanfic. His character would likely be different from the original series, having more unpredictable and chaotic traits.
Since it's a Percy - centered fanfic, Percy is surely one of the main characters. There may also be other characters from the Percy Jackson series like Annabeth, Grover, etc. who could be involved in the story to react to Percy's new identity as a child of Chaos.
There could be Sasuke. Since Naruto's situation changes, Sasuke might play a different role in this fanfic, either as an ally or a rival in a new way. Another might be Kakashi. He could be the one guiding Naruto through his discovery of being the son of chaos.