Well, Ash's Pokémon are a diverse bunch. His Heracross could use its Horn Attack to directly combat Team Rocket's Pokémon. Totodile could use its playful nature to confuse Team Rocket's Pokémon. And Ash's Bayleef could use its Razor Leaf to cut through any ropes or barriers that Team Rocket has set up to restrain Dawn. All of his Pokémon, with their unique abilities, would work together under Ash's command to save Dawn from Team Rocket.
One possible plot could be that Ash and Dawn are traveling together when Team Rocket attacks. Ash might use his Pikachu to fend off their initial attacks. He could then come up with a clever strategy, like using the environment to his advantage. For example, if they are near a body of water, he could make Team Rocket's Pokémon slip. Dawn, on the other hand, could use her knowledge of Pokémon contests to distract Team Rocket with some flashy moves from her Pokémon. In the end, Ash and Dawn manage to escape and continue their journey.
Yes, in some Team Rocket fanfictions, Ash can be depicted in various ways that might involve him having some sort of connection to Pokémon in a different light. Maybe he could be experimented on by Team Rocket to gain Pokémon - like abilities, or be transformed into a Pokémon - like being in a very creative and out - of - the - box fanfiction concept.
It would also have an impact on the other villainous teams in the Pokémon world. They might see Ash joining Team Rocket as a sign that they can also recruit more powerful trainers. This could lead to more alliances between the bad guys and more complex plots to steal Pokémon and cause trouble all around the Pokémon world.
The Pokémon League might condemn Ash's actions. Despite Team Rocket's wrongdoings, killing is not an acceptable solution in the Pokémon world which values friendship and co - existence. Ash could face consequences such as being banned from Pokémon battles or certain areas. On the other hand, some trainers who have been harassed by Team Rocket for a long time might secretly support Ash.
The fanfiction could start with Dawn being in a vulnerable situation, perhaps alone in an area where Team Rocket has set a trap. Ash, who has a sense of justice and cares about Dawn, discovers the situation. He then uses his knowledge of Pokémon battling, combined with his quick thinking, to outwit Team Rocket. His Pokémon work together as a team, and through a series of exciting battles and maneuvers, he manages to rescue Dawn from the clutches of Team Rocket.
He might become more cautious. Usually, Ash is quite bold and rushes into things. But if he's in a Team Rocket - centered fanfiction, he'd likely be more careful as he's constantly surrounded by danger. For example, he'd think twice before challenging a new Pokemon or entering an unknown area.
One possible role is that he could be a spy. Since he was turned into a Pokémon, Team Rocket might not suspect his true identity and he could gather information about their evil plans. For example, he could overhear conversations between Team Rocket members that he couldn't have accessed as a human.
Obviously, Ash and Dawn are main characters. Ash is the hero who comes to Dawn's rescue. Dawn is the one in need of being saved from Team Rocket. And of course, Team Rocket themselves are also important characters in this fanfiction as they are the antagonists.
Well, for one, Haunter has some really cool moves like Hypnosis and Dream Eater. When Ash catches it, his team's battle strategies would change. His other Pokémon would need to learn to work with Haunter. Also, Haunter's presence might intimidate some of the opposing Pokémon, giving Ash an edge in battles. It could also open up new exploration opportunities as Haunter might be able to access areas that other Pokémon on his team can't due to its Ghost - type nature.
The Pokémon League would be in shock. They would see Ash and Misty as traitors and would probably send out teams to capture them. Pokémon trainers who looked up to Ash would be very disappointed. They might start to question their own values and the values of the Pokémon training world.