Perhaps it would be a combination of forces that save Ash. His own Pokémon, led by Pikachu, could start the rescue mission. Along the way, they might encounter some friendly Pokémon trainers who offer their help. And there could also be some unexpected help from a Pokémon that Mew least expects. This Pokémon could have some sort of connection to Mew and be able to convince it to let Ash go or help Ash escape while Mew is distracted.
In the 'ash is kidnapped by mew fanfiction', one possible plot is that Mew is acting out of a sense of desperation. It might believe that by kidnapping Ash, it can save the Pokémon world from a greater threat. Ash, being the protagonist, would then have to find a way to communicate with Mew and figure out what's really going on, all while trying to escape. Another idea could be that Mew is simply misinformed about Ash and thinks he's a danger, so it kidnaps him to protect the Pokémon realm.
Pikachu would most likely be there. Since Pikachu is Ash's closest companion, it would be involved in any story related to Ash. Maybe Pikachu could also have some sort of interaction with Mew, like being a bit jealous at first of Ash's new connection with Mew.
Pikachu would be a likely candidate. Pikachu is Ash's most loyal Pokémon and has a very strong bond with him. It would sense that Ash is in trouble and would go on a mission to rescue him. Pikachu could use its electric attacks to fight off Gary or any obstacles in the way.
Perhaps in this fanfiction, Ash discovers that he has a deeper connection to Mew than he ever thought. It could involve Mew choosing Ash as a special trainer to carry out a very important mission in the Pokémon world, such as saving a certain region from a new and powerful threat. This would lead Ash to face many challenges and grow in ways he hasn't before.
A powerful and greedy Pokémon collector could be the main antagonist. He wants to capture Ash, now in his Mew form, to add to his collection. He has all sorts of high - tech devices and trained Pokémon to try and catch Ash.
Maybe a powerful and envious Mewtwo could be the antagonist. Since Ash has now become a Mew, Mewtwo might feel threatened or think that Ash doesn't deserve such power. So, Mewtwo could try to fight Ash to prove his own superiority.
A new villainous trainer group. They might see Ash as a threat to their plans of dominating the Pokémon world, so they kidnap him to stop him from competing in important battles or tournaments.
One possible plot could be that Ash has a strange encounter with a Mew. Maybe he discovers a hidden power within himself that is related to Mew. This new power could attract Mew to him, and they form an unexpected bond. Ash then has to learn to control this new power while also facing challenges from other trainers who are jealous of his newfound connection with the rare Pokémon Mew.
Well, perhaps Ash could be transformed into a Mew through some magical encounter. He might then use his new form to explore the Pokémon world in ways he couldn't before, like flying high above the clouds and seeing the landscapes from a whole new perspective.
In fanfiction, the relationship between Ash and Female Mew can be very interesting. It often involves unique storylines where Ash might encounter Mew in a different context than in the original Pokémon series. For example, the fanfiction could explore how Ash's adventures change when he has a special bond with Female Mew. Maybe they go on a journey together to discover new Pokémon or face a powerful enemy that only they can defeat as a team. This relationship in fanfiction can bring out different aspects of Ash's character, such as his compassion and determination in a new light.