In addition to Ash, May would be a key character. She has her own goals in Hoenn, like competing in contests, and her presence could add a different dynamic to Ash's journey. Then there's Max, May's little brother. He could be the one who always has some interesting facts about Hoenn's history and Pokemon. And of course, Team Aqua and Team Magma members could be important characters as they create various challenges for Ash throughout the story.
Definitely May. Since it's in Hoenn, she's a likely character. She might start as a rival to Ash but then they become friends. Also, Professor Birch could play an important role. He could be the one guiding Ash in his initial days in Hoenn, providing him with his first Pokemon and some basic knowledge about the region.
May could be one of the main characters. She could join Ash on his journey and share her knowledge about Hoenn's Pokemon with him. Another could be Brock, still tagging along to offer his expertise in Pokemon care.
One possible plot could be Ash starting his journey in Hoenn, meeting new Pokemon like Treecko as his first partner. He might encounter Team Aqua or Magma early on and get involved in their schemes to control the weather or the land. He'll also face gym leaders, learning new battle strategies along the way.
One possible fanfiction could be about Ash's adventures in Hoenn during the month of May. Maybe he discovers a new Pokémon species that is only active during this time of the year. He could be traveling with his usual companions and facing challenges specific to the Hoenn region.
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.
A young girl named Mia might be a character too. She is also a Glacion fan and is very competitive. She challenges Ash to various Glacion - related challenges, like a Glacion knowledge quiz or a race to find a hidden Glacion item in the forest.
In this fanfiction, Gary could be an important character. Since he has always been in competition with Ash, he might have mixed feelings about Ash being the chosen one. Serena could also be a main character. She might be inspired by Ash's chosen - one journey and decide to follow him, offering her own skills and support. Professor Oak would likely be involved as well, guiding Ash with his vast knowledge of Pokémon.
Well, Pikachu could still be a main character. Even if Ash hates everyone, Pikachu might be the one trying to bring back the old Ash. Maybe Team Rocket could also be main characters. They are always around Ash, and his new - found hatred could make their interactions even more interesting. They might be confused by his change or even try to take advantage of it.
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.
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.
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.
It could be that there is a young, impressionable character who looked up to Ash Aura. After the betrayal, this character is confused and starts to question his own beliefs. There might also be a powerful mage in the story who has the ability to see the truth behind Ash Aura's actions and is trying to prevent the chaos that the betrayal has caused.