Some of the more intelligent Pokemon on his team, like Bulbasaur or Squirtle, might try to find a way to reverse the transformation. They could search for special herbs or items in the Pokemon world that they think could help Ash return to his normal state. And during this process, they would have to protect Ash from any potential dangers that his new form might attract.
The Pokemon that have been with Ash for a long time, like Snorlax, might have a deeper connection with him and be able to sense that it's still Ash, even though he looks like a hedgehog. Snorlax might be more accepting right away and try to protect Ash from any potential danger. On the other hand, the newer members of his team might be more likely to question whether this hedgehog - like Ash is still their rightful trainer. But as time passes, they would all start to realize that Ash's spirit and his bond with them haven't changed, despite his physical transformation.
Pikachu would probably be very confused at first. It's used to fighting against Team Rocket, not being on their side. It might resist and try to zap Ash to snap him out of it.
Pikachu would likely be very confused and resistant. Pikachu has a strong bond with Ash and knows his true nature. It would probably try to shock Ash out of whatever trance or false belief he has from joining Team Galactic. For example, when Ash starts to follow Team Galactic's orders that go against his usual principles, Pikachu might refuse to cooperate and try to show Ash that he's on the wrong path.
Some of his more loyal Pokemon might try to resist the change. For example, Pikachu could use electric shocks to try and jolt Ash back to his senses. Pikachu has a strong bond with Ash and would be very confused and sad about his decision to join Team Rocket.
Ash would probably be devastated. He would feel like his world has been turned upside down. At first, he might not believe it and think it's all a big mistake. As the reality sinks in, he could start to isolate himself from others, even from his Pokemon for a while. However, his strong will would eventually kick in. He would use this as motivation to become stronger, not just in his Pokemon battles but also in his ability to face challenges alone, without relying on his so - called friends.
His Pokemon might be a bit confused at first. Pikachu, for example, is used to their adventures on the road. But they'll soon adapt. They could make new Pokemon friends at the school too. And they'll be there to support Ash during his school challenges, like in battles or tests.
His birth year might mean he has a preference for older or more classic Pokemon. For example, he could be more likely to choose Pokemon like Bulbasaur, which has been around for a long time in the Pokemon world. Since he was born in 1987, he might have grown up hearing stories about certain Pokemon and be more drawn to them for his team.
His Pikachu would probably be very supportive. It would stay by his side as he studies, maybe even help him in small ways like fetching medical tools. It trusts Ash completely and would be happy to see him pursue something new.
Well, one thing that could happen is that Ash's transformation could lead to him having new and strange abilities. Maybe he could communicate with Pokemon in a whole new way, like directly understanding their thoughts and feelings without the need for words. This would completely change his approach to battles and his relationships with his Pokemon friends.
Ash has always been a defender of Pokemon. If he found out about Team Plasma's experiments, he would first try to understand the full scope of what they were doing. Then, he would use his experience and his Pokemon team's skills to fight against Team Plasma. He might also try to convince some of the members of Team Plasma that what they are doing is wrong, as he has a way of seeing the good in people. Ash would be very determined and would not give up until he put an end to the experiments.