Maurice is also quite interesting. His intelligence and his kind heart towards both apes and humans, if he were to cross paths with Ash, could lead to some really heart - warming or thought - provoking interactions. He often serves as a voice of reason among the apes.
Caesar is definitely one of the most intriguing characters. His leadership among the apes and his complex relationship with humans make him a very interesting character to interact with in fanfiction. He has a strong sense of justice and is constantly trying to find a balance between the ape and human worlds.
Pikachu is always an interesting character in these fanfictions. In some stories, Pikachu might develop new abilities or have a deeper understanding of the Pokemon world that it can share with Ash. Another character could be Gary. He can be portrayed as a more complex rival, perhaps with his own hidden motives or a change of heart towards Ash. And then there's Misty. She can have new storylines in fanfictions, like being a powerful water - type Pokemon trainer with her own unique training methods that Ash can learn from.
Lillie is really interesting. She starts off as a shy girl but grows a lot in her confidence when it comes to Pokemon. Her relationship with her family and their connection to the Aether Foundation adds depth to her character. Then there's Kiawe, who is very proud of his Alola heritage and his strong fire - type Pokemon. His no - nonsense attitude and his eagerness to prove himself make him stand out. And Sophocles, the tech - savvy kid, is always coming up with cool gadgets to help in Pokemon battles or exploration, which is super fun.
One interesting character could be an alternate version of Misty from another dimension. Maybe she's a powerful water - type Pokemon trainer who has mastered techniques that the original Misty hasn't. Another could be a dimension - hopping researcher who is trying to study the different dimensions and their Pokemon. He could be a source of knowledge for Ash, guiding him through the mysteries of the new dimensions. There could also be a villainous character who is causing chaos across the dimensions by stealing rare Pokemon or disrupting the balance between different dimensions.
A third storyline could be Ash's discovery of a hidden human enclave in the Planet of the Apes. He then has to decide whether to stay with the humans or continue his life among the apes. This would involve moral dilemmas as he weighs the pros and cons of each option, all while trying to keep his presence a secret from the more hostile apes.
Brock could also be a main character. Since he has knowledge about Pokémon care and breeding, he could be Ash's colleague in the fanfiction. They could work together on projects related to Pokémon health and nutrition.
The OC themselves are often popular characters. Since they are original creations, they can have all sorts of unique personalities, abilities, and backstories. For example, an OC could be a shy but brilliant Pokemon trainer who gradually overcomes their insecurities with Ash's help.
Pikachu would most likely be there. Since Pikachu is Ash's closest companion, it would be involved in any story related to Ash. Maybe Pikachu could also have some sort of interaction with Mew, like being a bit jealous at first of Ash's new connection with Mew.
Latios would obviously be a key character. Also, Pikachu, Ash's loyal Pokémon partner, would be there. Maybe Misty or Brock could also be part of the story, with them either supporting or being skeptical of Ash's newfound admiration for Latios.
Team Rocket might be main characters as well. They could be constantly trying to capture Ash or his Pokemon because of his special status. Their bumbling attempts to take advantage of Ash's link to Arceus could add a lot of comical and action - filled moments to the fanfiction. And of course, Arceus itself could be a major character, guiding Ash in some way or interacting with him directly.
Obviously, the Legendary Pokemon would be a main character. It could be a Pokemon like Mewtwo, who is often depicted as having a complex personality. It might start off as a mysterious and powerful entity that Ash has to befriend or battle against.