A fellow trainer who Ash considered a friend could be the betrayer. This trainer might have been secretly envious of Ash all along. When Ash reaches the pinnacle of success in Kalos by becoming champion, the envy boils over and the trainer betrays Ash, perhaps by trying to steal his Pokémon or undermine his reputation.
One likely betrayer could be Serena. Maybe she has some hidden motives that are revealed when Ash becomes champion. For example, she might be jealous of his success and the attention he gets as champion, and so she betrays him.
One possible plot could be that Ash's so - called friends in the Kalos region turn on him out of jealousy. Maybe they can't handle the fact that he has become the champion. They start spreading false rumors about him, which makes the public turn against Ash. This betrayal could lead Ash to question his own journey and the relationships he has formed.
A great 'Ash becomes Kalos Champion' fanfiction would have a strong sense of progression. Ash should start at a certain level and gradually become more powerful as he overcomes various obstacles in Kalos. The fanfiction could also explore the backstories of his Pokémon in more detail, like how they came to be with Ash and what their own goals are. Additionally, the way Ash interacts with the local Pokémon and trainers in Kalos can add depth and authenticity to the story.
One possible fanfic could be about Ash's journey to become the Kalos champion. It might start with his arrival in Kalos, full of excitement and determination. He meets new Pokémon and friends along the way. His battles are intense, with him using unique strategies to defeat his opponents and gradually climb the ranks to the championship.
Ash would likely be shocked at first. He's so used to seeing the good in people, especially fellow trainers. But then he'd probably get angry and determined to set things right. He has a strong sense of justice, so he wouldn't let the betrayal go unpunished.
It could be a local Kalos trainer who has been training specifically to become the Kalos champion for years. This trainer might have a team of rare and powerful Kalos Pokémon and a very strategic battle style. He or she could see Ash as an outsider and a threat to their long - held dream of being the champion.
One possible scenario in this fanfiction could be that Ash has to overcome his toughest opponents yet in Unova. He might face trainers with unique and powerful Pokémon that he has never encountered before. His Pikachu would surely play a crucial role, using its speed and electric attacks to outwit opponents.
One idea could be Ash facing a new, extremely powerful and mysterious Pokémon in the Kalos region that no one has ever seen before. This Pokémon could be the key to a hidden power within the Kalos champion title. Another plot could involve Ash having to team up with a former rival from his past travels to overcome a threat to the Kalos Pokémon ecosystem. Maybe there's a dark organization trying to disrupt the balance, and Ash's unique bond with his Pokémon is what's needed to stop them.
In an Ash betrayed champion fanfiction, perhaps the champion has been secretly working with a villainous group. The champion lures Ash into a trap under the pretense of a friendly battle. Ash, being trusting, falls for it. He then has to find a way to escape and get revenge. He might meet some new allies along the way who help him see the champion's real motives.
A fellow trainer in Alola could betray Ash. This trainer might be envious of Ash's success as a champion. He could secretly work with Team Skull or some other antagonists to undermine Ash. For instance, he might give false information to Ash about a battle location, leading Ash into a trap.
Maybe Team Rocket. They've been after Ash for a long time. If Ash comes back as a champion, they might see it as a threat and betray him in some way. They could pretend to be his friends at first and then stab him in the back to get what they want, like his powerful Pokémon or his championship title.