Team Rocket is commonly seen in 'evil Ash' fanfiction. Jessie, James, and Meowth might take advantage of Ash's new evil persona. They could see him as a valuable ally in their schemes to steal Pokemon. In some stories, they might even be the ones who initially lead Ash down the wrong path, by tempting him with power or rare Pokemon.
Another character that might show up is Professor Oak. He could be shocked to see Ash's transformation and try to find a way to reverse it. He might use his knowledge of Pokemon and science to figure out what has caused Ash to turn evil. His presence would add an element of wisdom and authority to the story.
Obviously, Ash is a central character. Pikachu is also often there, as it's Ash's main Pokemon. Misty and Brock might be in the fanfiction too, trying to figure out what has happened to Ash and how to stop his evil ways. Sometimes, Gary Oak could be involved, either as an antagonist to Ash's new evil self or as someone trying to help bring him back to the good side.
Well, clearly Ash and Serena are the main characters. Ash, in this case, is the 'evil' version, which is a departure from his usual good - natured self. Serena is likely to be the one who tries to bring back the old Ash or at least stop his evil deeds.
Ash is of course a very common character as he is the central figure. Pikachu is also often included as it is Ash's most well - known Pokémon. Other characters like Misty and Brock might also make appearances as they are Ash's friends and travel companions in the original Pokémon series.
Obviously, Ash is a common character. His friends like Brock and Misty might also make appearances. They could offer their own skills and knowledge to help Ash in his ranger adventures.
Some fanfictions might also include new characters that Ash meets on his return journey. These could be trainers with unique Pokemon or mysterious characters who have a connection to the events that led to Ash's return. For example, a young trainer who idolizes Ash and wants to learn from him, or a character who has information about a powerful Pokemon that Ash is interested in.
Ash is obviously a very common character as the title includes his name. Pikachu, his trusty partner, is also likely to be there. His friends like Brock and Misty often appear as well. They might support Ash during his league journey or have their own sub - plots related to the league.
Gary could be a common character in such fanfiction. Since he's Ash's long - time rival, it makes sense for him to show up at the Battle Tree. He might be there to test his skills against Ash or to prove himself as a better trainer.
Professor Kukui is another common character. He serves as a guide and mentor to Ash in the Alola region. He might provide Ash with new Pokémon knowledge, especially about the unique Alola Pokémon species. And of course, there are the various Pokémon trainers that Ash meets and battles in the Alola region. These trainers can range from novice trainers just starting out to more experienced ones who pose a real challenge to Ash.
There are also often appearances from various Gym Leaders. They can serve as either allies or rivals to Ash. For instance, a Gym Leader might challenge Ash to a battle to test his newfound power, or they could join forces with him to take on a greater evil that threatens the Pokemon world.
Pikachu is definitely a common character. It's Ash's most loyal partner and is always by his side during his adventures. Serena is also often present. She has her own dreams and goals related to Pokemon and often travels with Ash, providing support and sometimes even competing with him.
Misty is a very common character. She was one of Ash's earliest companions. In fanfiction, she is often portrayed as his girlfriend because of their long - standing friendship and the chemistry they had during their travels. They bickered like an old married couple at times, which could easily be developed into a romantic relationship in fan - created stories.