Well, first of all, the perception of Team Rocket in the Pokémon world would change drastically. People would be confused and worried about Ash leading them. In terms of Pokémon - related activities, Ash could introduce new training methods to Team Rocket members. This might make their captured Pokémon stronger and more difficult to defeat for other trainers. Also, Ash could use his influence to make Team Rocket more involved in Pokémon conservation in a strange way. For instance, he might steal Pokémon from trainers who are not taking proper care of them and then place them in better environments. This would create a whole new set of rules and power dynamics in the Pokémon world, as other organizations and trainers would have to adjust to this new Team Rocket.
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.
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.
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.
If Ash was secretly a Pokémon, trainers might view Pokémon in a whole new light. They would see that Pokémon could be more like them, with complex emotions and motives. Also, Ash's relationships with other Pokémon and trainers would be re - evaluated. His Pokémon friends might see him as an equal rather than just a trainer.
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.
His team might gain some new Kalos Pokémon. For instance, he could catch a Fennekin which later evolves into Delphox. This new addition would bring in new moves and abilities. Maybe he would also trade one of his existing Pokémon for a unique Kalos Pokémon that has a special advantage in the Kalos battles.
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.
The Pokémon might initially think it's some sort of joke or mistake. But as time goes on, if Ash seems serious about being with Team Rocket, they could become divided. Some of the more headstrong Pokémon might leave Ash, while others might stay with him out of loyalty but still be unhappy about the situation. They would be constantly trying to nudge Ash back to his old ways of being a good Pokémon trainer.
One idea could be that Ash, as the leader of Team Rocket, uses his knowledge of Pokémon in a new way. He might focus on stealing rare Pokémon not just for evil purposes but to prove a point about Pokémon training ethics. For example, he could target trainers who mistreat their Pokémon and then 'liberate' the Pokémon into a better environment he creates. Another plot could involve Ash leading Team Rocket in a new direction of cooperation with other Pokémon organizations. Instead of always being the bad guys, they could form alliances to solve some of the more complex problems in the Pokémon world, like dealing with a new, powerful and dangerous Pokémon species that threatens the balance of nature.