Maybe a new, mysterious villain who has a grudge against Ash or wants to use his skills for their own evil purposes. This villain might be from a far - off region and has special powers that allow them to hypnotize people. They see Ash as a useful tool to carry out their plans in the Pokémon world.
There's also a possibility that it's an experiment gone wrong. Some Pokémon researcher might be testing a new type of mind - control technique on Pokémon and accidentally hypnotizes Ash instead. The researcher realizes too late what has happened and now Ash is under the spell to obey, causing all sorts of problems in the Pokémon world.
One possible plot could be that a villain uses hypnosis on Ash Ketchum to make him do their bidding in Pokémon battles. So instead of using his own strategies, he's forced to follow the commands of the hypnotist. This would create a lot of chaos and challenges for his friends as they try to figure out what's wrong with Ash and how to break the hypnosis.
One possible fanfiction could involve Team Rocket using a new device to hypnotize Ash Ketchum. They might make him do silly things like singing a Pokémon theme song in a really strange voice or making Pikachu do a little dance. But of course, his friends would eventually figure out what's going on and try to break the hypnosis.
One possible fanfiction could be where a powerful Pokémon trainer with psychic abilities hypnotizes Ash Ketchum. In this story, the trainer might have an evil plan to use Ash to steal rare Pokémon. Ash, under the hypnosis, starts to obey commands against his will. However, his Pikachu senses something is wrong and tries to break the hypnosis by using its electric shocks on Ash at just the right moment. Eventually, Ash breaks free and battles the evil trainer.
The plot could be that an unknown villain hypnotizes Ash. The villain wants to use Ash's skills and reputation to steal Pokémon. Ash, under hypnosis, starts to lead other trainers into traps. His friends are confused at first but then realize he's not himself. They search for a way to reverse the hypnosis, perhaps by finding a rare Pokémon or a special item.
Well, if Ash was hypnotized to obey commands in fanfiction, it might change the whole dynamic of his adventures. For example, Team Rocket could get hold of the hypnosis method and try to make Ash work for them. But Ash being Ash, even under hypnosis, his love for Pokémon might break through the commands and he could end up turning the situation around on Team Rocket.
Well, the concept of Ash having to obey is interesting because it can completely change the dynamics of his relationships. His Pokémon, his friends, and his rivals will all interact with him differently. It also allows the author to explore different plotlines and scenarios that wouldn't be possible in the normal Pokémon storyline where Ash is more independent.
Well, this type of fanfiction concept often delves into the realm of the psychological. The idea of mind control over Ash Ketchum can be seen as a way to play with power dynamics. If a villain is the one controlling him, it gives the villain an upper hand in a different way compared to just physical strength. And it forces the fanfiction writer to think about how the Pokémon world's rules and magic could be bent or used in relation to hypnosis. Also, it can open up opportunities for exploring different moral and ethical questions within the story, like whether it's right to use mind control, and how far his friends should go to free him.
There could be a fanfiction where Ash is magically bound to obey a mysterious force. This changes his whole approach to Pokémon battles. Instead of his usual impulsive style, he has to carefully plan and execute his moves according to the commands of this force. It makes for a really different and exciting take on his character.
His rival, Gary, could be a likely candidate. Gary has always been competitive with Ash, and in this fanfiction, his jealousy could reach a boiling point, causing him to betray Ash for his own gain, like trying to steal his Pokémon or get credit for his achievements.
One common plot could be that Ash gets hypnotized by a mysterious Pokémon trainer who wants to use his skills for their own gain. For example, they might want to win a big tournament using Ash's battle knowledge. Another plot could involve Ash being hypnotized and made to forget his friends, Pikachu included, and then his friends have to find a way to break the hypnosis. It could also be that a villain hypnotizes Ash to make him steal Pokémon for them.