A common theme in fanfiction where Ash is betrayed for revenge is the idea of self - discovery. If he was betrayed by someone he thought was a mentor, he might go on a journey of self - discovery to find his true strength. And then, he would use this new - found strength to take revenge. He could develop new training methods for his Pokémon and come back stronger than ever to face his betrayer.
One possible revenge scenario in the fanfiction could be that Ash was betrayed by a close friend in a Pokémon journey. Maybe his so - called friend stole his Pokémon. So, in revenge, Ash might train harder, find new and powerful Pokémon, and then challenge his betrayer in a huge battle. He could use his new skills and Pokémon to defeat the one who wronged him, regaining his honor and his Pokémon.
Betrayal could also stem from a misunderstanding. Maybe Ash or Cynthia accidentally offend someone without realizing it. For example, they might unknowingly step on a trainer's dreams or beliefs. And that trainer, feeling deeply hurt, decides to betray them. Or it could be that a Pokemon they both have a connection with has a different loyalty that they were not aware of, which leads to the Pokemon causing their betrayal.
At first, Ash would be in shock. But then, he would likely turn his focus on finding out the truth. He's not one to give up easily. He'd start investigating what led to his betrayal. He might even go on a journey within the RWBY world to find evidence to clear his name and expose those who really are at fault. He'd still hold out hope that his former friends would see the truth and come back to his side.
One possible plotline could be that Ash is betrayed by his so - called friends in the Pokémon world. They might spread false rumors about him, making everyone turn against him. Meanwhile, Mewtwo, who has formed an unlikely bond with Ash, is also betrayed by the scientists who created it again. They try to recapture Mewtwo to use it for their evil experiments. Ash and Mewtwo then team up to fight against their betrayers and prove their worth.
Jealousy could be one reason. Maybe his friends are jealous of his achievements as a Pokémon trainer. Another reason could be that they are influenced by some external forces, like an evil organization that convinces them to betray Ash.
One possible plotline could be that Ash and Cynthia are betrayed by a powerful and long - hidden organization in the Pokemon world. Maybe they are lured into a trap under false pretenses. For example, they are told there is a great Pokemon discovery but it's actually a setup to steal their Pokemon or get some important information from them. Another could be a betrayal from a so - called friend. This friend might be jealous of their achievements and decides to side with an enemy to bring them down. This could lead to Ash and Cynthia losing battles they should have won and facing challenges that seem insurmountable at first.
One possible plot could be that Ash, being from a different world, is initially welcomed into the RWBY universe. But then, he might be betrayed when his Pokémon powers are seen as a threat. Maybe the RWBY characters fear that his abilities could disrupt the balance of their world. For example, if his Pikachu's electricity causes unexpected power surges in a world that has its own unique energy sources like Dust.
It could be that Arceus betrays Ash by revealing that all of Ash's Pokemon encounters and relationships were fabricated. Arceus made it so that Ash would form bonds with certain Pokemon to further its own ends. For instance, Arceus wanted to study the power of friendship among humans and Pokemon through Ash's experiences. When Ash finds out, he feels used and betrayed. He might then set out on a journey to free his Pokemon from Arceus' control and restore their true free will.
Well, often in such a 'ash gets betrayed fanfiction', the story might start with a seemingly normal day for Ash. Then, out of the blue, someone he trusts deeply, like Pikachu or one of his human friends, does something that he perceives as a betrayal. This could be something as simple as not believing in him during a crucial battle or siding with an enemy for a reason that's not clear to Ash at first. It can create a lot of emotional turmoil for Ash and make for a very engaging read.
One possibility could be that in the fanfiction, Ash betrays Latias out of a misunderstanding. Maybe he was tricked by a villain into believing that Latias was a threat to the region. This would create a lot of drama and conflict in the story as Latias, who probably trusted Ash, would be deeply hurt.