In a fanfiction where Serena joins Team Rocket, it would likely change her character development significantly. She would be exposed to the more devious side of the Pokemon world. Team Rocket might try to use her as a tool to get closer to Ash and Pikachu. However, Serena could also try to reform Team Rocket members. For example, she could try to convince Jessie, James, and Meowth that there are better ways to interact with Pokemon than stealing them.
Well, if Serena joins Team Rocket in a fanfiction, she might bring a new dynamic. Maybe she's forced to join at first. She could use her skills in battles and her knowledge of Pokemon to help Team Rocket in their schemes, but secretly she could be planning to take them down from the inside.
Another possibility is that Serena discovers a secret within Team Flare that could change the whole dynamic of the Pokemon world. It could be a powerful weapon or a hidden plan that is far more dangerous than anyone thought. She then has to decide whether to use this information to her advantage within the team or to try and get it out to the people who can stop Team Flare. This would put her in a very difficult position as she's already in deep with the team.
Well, in such a fanfiction, Ash might start using Team Rocket's sneaky tactics. He could learn from them how to be more devious in catching Pokémon. For example, he might use their elaborate traps instead of his usual straightforward battles. This would be a huge change from his normal good - guy image.
Well, if Misty joins Team Rocket in fanfiction, it would be a huge shock to the other characters. Her friends like Ash would be completely bewildered. Maybe she's been tricked into it somehow, like being deceived by Team Rocket's false promises. This could lead to some really interesting plot twists. For example, she might be used to set traps for Ash and the others, but deep down still have some good in her that causes internal conflict within Team Rocket.
Ash joining Team Rocket could lead to some interesting character dynamics. He might start to question his own values. For instance, he's always been about friendship with Pokemon, but Team Rocket is more about using them for gain. This internal conflict could be a major part of the fanfic. Also, his relationship with Jessie, James, and Meowth would change drastically.
Well, it could make for a really interesting fanfiction. Dawn joining Team Rocket would change the whole dynamic. Her Pokémon might not be too happy about it at first. She could bring new ideas to Team Rocket, since she has a different way of thinking compared to Jessie, James and Meowth. However, it's also possible that she would secretly be working against Team Rocket from the inside, trying to take them down while pretending to be one of them.
Well, if Ash joined Team Rocket, he'd probably bring a whole new dynamic. His skills as a trainer could be used in unexpected ways. Maybe he'd try to reform Team Rocket from the inside, using his kind heart and love for Pokémon to change their ways. He could also introduce new strategies for capturing Pokémon that are more ethical than Team Rocket's usual methods.
In a fanfiction where Ash joins Team Rocket, it could lead to some really interesting storylines. Ash has a lot of knowledge about Pokémon training that Team Rocket lacks. He could potentially teach them new techniques, but at the same time, his moral compass would be constantly at odds with their devious ways. Maybe he joins them because he's somehow tricked or he has his own secret plan to take them down from the inside. It would be a great opportunity to explore different aspects of his character and how he adapts to this new situation.
Another thing that could occur is that Ash's friends would be very suspicious. They might think Ash has gone to the dark side. So they could try to rescue him. This would lead to a lot of drama and action. There could be epic battles between Ash's friends and Team Flare while Ash is caught in the middle, trying to figure out what to do and where his loyalties truly lie.
One possibility is that Ash brings his unique battle skills to Team Skull. He might start teaching the members new strategies, which could change the whole dynamic of the team. For example, his bond with his Pokémon could inspire the Team Skull members to form stronger relationships with their own Pokémon.
If Team Rocket turns Ash into a Pokemon, his relationship with his old Pokemon would change. His Pokemon might not recognize him at first. But as they sense his familiar spirit, they could try to protect him. And Ash, in his new form, could learn a lot about the true nature of Pokemon. He could discover secrets about their evolution, abilities, and the hidden powers within them that he never knew as a human trainer.