Perhaps the story could involve Ash being transformed into a Pokémon through some magical or scientific experiment gone wrong. As a Pokémon, he would join a group of other Pokémon on a journey. He might face challenges like being hunted by Pokémon hunters or having to prove himself to a Pokémon tribe. Along the way, he'd also learn about the different perspectives of Pokémon in their own world.
In this fanfic, it could be that Ash is turned into a Pokémon by an evil villain who wants to use his knowledge of the Pokémon world against him. Ash, now as a Pokémon, has to find a way to break the spell. He teams up with his old Pokémon friends, but they have to get used to him being in a different form. They go on adventures together, facing off against the villain's minions and trying to find a cure, all while Ash discovers new things about the Pokémon world from his unique perspective.
Maybe Ash discovers a hidden power within himself that is linked to the legendary Pokemon. This power could be awakened through a series of dangerous adventures, like facing off against an evil team that is trying to capture all the legendaries. As he progresses, he gradually transforms into a being with some of the abilities of a legendary Pokemon.
Well, perhaps Ash starts to idolize Pikachu after seeing its unique powers in a battle. He might try to imitate Pikachu's moves and even start collecting Pikachu - themed items.
In the 'pokemon ash becomes a charmander fanfiction', it could be that Ash witnesses a Charmander perform an incredibly heroic act. For example, saving a group of Pokemon from a dangerous situation. This act of selflessness and courage makes Ash look at Charmander in a whole new light. He starts to study Charmander's behavior, training techniques specific to Charmander, and even starts collecting Charmander - related items. He becomes so obsessed that he starts to model his whole Pokemon - training approach around what he has learned from Charmander.
Well, it could be about Ash waking up one day as a girl and having to deal with all the changes in his, now her, life. Maybe she has to adjust to new social dynamics, different reactions from friends and rivals, and also how to handle Pokémon battles in a different body.
In this fanfic, it could be that Ash is turned into Pikachu as a result of an experiment gone wrong. As Pikachu, he discovers new abilities and senses that he didn't know about before. He might form closer bonds with other Pikachu in the wild and learn their ways of living. He could also have to face challenges like being hunted by other Pokémon that see him as an easy target, and he has to use his new Pikachu - like skills to survive and try to find a way to turn back into his human form.
Well, one possible plot could be that Ash decides to become a Frontier Brain to test his skills further. He might start by traveling to different Frontier areas, facing various tough opponents and their unique Pokémon. Along the way, he could learn new training techniques and battle strategies, all while inspiring other trainers with his determination.
It could be Team Rocket. Since they always cause trouble for Ash in the original series, in this fanfic, they might see Ash's transformation into a Pokémon as an opportunity to capture him and use him for their evil plans.
In a fanfic, it could be that Ditto is a key to unlocking a hidden mystery in the Pokemon world. Ash, being the curious and adventurous trainer he is, teams up with Ditto to explore this mystery. They might travel to unknown regions, meet new Pokemon species, and have to battle against powerful and unknown foes along the way. As they progress, Ash learns more about Ditto's true nature and how it relates to the overall mystery.
In such a fanfiction, perhaps it could involve Sabrina being in a situation where she has to follow Ash's commands due to some magical or strange circumstances. Maybe Ash unknowingly stumbles upon a power that binds Sabrina to him, and then he has to figure out how to deal with this new relationship while also continuing his pokemon journey.
In the fanfic, Ash could enter a major coordinator competition where he faces off against some of the toughest opponents. He might struggle at first because he's used to traditional Pokemon battles. But as the competition progresses, he starts to understand the nuances of coordinator battles better. His friends could also play important roles, like Misty giving him advice on how to make his Pokemon's water - based attacks look more appealing, and Brock helping with Pokemon health and grooming to ensure they look their best during the shows.