One possible storyline is that Dawn joins Team Rocket thinking it's a legitimate Pokémon training organization at first. But as she gets deeper into it, she discovers their true evil nature. Another could be that she is brainwashed by Team Rocket into joining them. Her friends then have to find a way to break the brainwashing. A third storyline could be that she joins willingly because she has some sort of vendetta against the Pokémon League and sees Team Rocket as a way to get revenge.
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.
Maybe there's a rogue Pokemon trainer. This trainer is jealous of Dawn's skills and the attention she gets. When Dawn joins Team Rocket, this trainer sees it as a chance to expose her as a fraud. He or she then tries to stop Dawn and Team Rocket's activities, thinking that they are up to no good, which they are, but the trainer has his own self - centered motives.
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.
One possible plot could be that Dawn, for some reason, gets disillusioned with her regular Pokemon journey. Maybe she has a series of losses that make her question her methods. Team Rocket, seeing an opportunity, convinces her that they have a better way to train and use Pokemon. She then joins them, initially helping with their small-time schemes, but gradually realizes that their actions are unethical and has to find a way to break free.
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.
Well, in such a fanfiction, the plot might involve Team Rocket devising a clever plan to capture Dawn. Maybe they use some new and devious Pokémon or traps. They could be after her Pokémon for some evil scheme, like using them to take over a Pokémon Contest Hall.
Well, if Ash joins Team Rocket in a fanfic, it would be a huge shift in the Pokemon world. His friends, like Misty and Brock, would be shocked. They might try to rescue him. Ash, on the other hand, could initially be attracted to the idea of a new adventure with Team Rocket. He could see them as underdogs in a way, always failing but still trying. But as time goes on, he'd start to see the problems with their way of doing things.
It could lead to some really unexpected and exciting plot twists. Ash's alignment with Team Rocket would completely change the dynamics of the story.
In a 'pokemon dawn joins team galactic' fanfiction, the plot could involve Dawn being lured by Team Galactic's false promises of power. Maybe they convince her that their goals for the Pokemon world are noble at first. She might start to question her own values and the way she has been training Pokemon. However, as she delves deeper into Team Galactic, she could discover their true evil intentions and then have to struggle to break free and redeem herself.
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.