His rivals could be the ones to betray him. For example, Gary Oak might see Ash's godlike powers as a threat to his own status and decide to plot against him. Gary could spread false rumors about Ash to turn others against him.
It could be a Pokémon that Ash has a special bond with. If the Pokémon gets influenced by some dark force, it might turn on Ash. This would be a huge betrayal as Pokémon and their trainers usually have a very deep and trusting relationship.
Maybe a new, mysterious character in the fanfiction. This character could be envious of Ash's power and popularity. So, they manipulate Ash's friends into believing that Ash is up to no good, which would be a form of betrayal from Ash's friends' side.
His rival, Gary, could be a likely candidate. Gary has always been competitive with Ash, and in this fanfiction, his jealousy could reach a boiling point, causing him to betray Ash for his own gain, like trying to steal his Pokémon or get credit for his achievements.
In certain fanfictions, a Pokémon professor or an authority figure in the Pokémon world could betray Ash. They may have their own secret agendas. For example, a professor might use Ash's research data without his permission or manipulate him into dangerous situations for their own experiments. This would make Ash feel extremely betrayed as he looks up to these figures for guidance.
Well, without actually reading the specific fanfiction, it could be about Ash Ketchum, who is in a 'godlike' state, being betrayed by someone. Maybe his friends turn against him due to jealousy of his newfound power. Or perhaps an enemy manages to deceive those close to him, making them think Ash has done something wrong when he hasn't.
The 'godlike psychic Ash Ketchum fanfiction' might be about Ash's transformation into a being with extraordinary psychic powers. These powers could give him the ability to foresee events, manipulate the environment around him, or even influence the minds of other trainers and Pokémon. It could also be a story about how he struggles to control these new powers, as they are so powerful that they might be overwhelming at times. His friends like Brock and Misty could play important roles in helping him come to terms with his new abilities and use them for good.
It could be a famous Pokémon trainer. Maybe someone who has traveled to many different regions and has a lot of knowledge about rare Pokémon.
It could be Gary. Gary has always been a rival to Ash. Maybe in this fanfiction, Gary gets jealous of Ash's progress and decides to betray him by making false accusations to the Pokemon League about Ash using illegal training methods.
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.
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.
His rival could be the one to betray him. Rivals are often jealous and competitive. If Ash's rival saw an opportunity to gain an advantage by betraying him, they might do it. For instance, they could lie about Ash to the Pokémon League, getting him disqualified from important battles.
It could be his rivals. For instance, Tracey or Paul might see Ash's potential in the new region as a threat and decide to betray him. They could try to sabotage his battles by giving false tips to his opponents or stealing his battle strategies.