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.
Maybe in the fanfic, a mad scientist creates a device that accidentally swaps Ash's essence with Mew's. As Mew - in Ash's body - Ash has to figure out how to reverse the process while also dealing with Team Rocket, who notice something very strange about 'Ash'. Meanwhile, the real Ash, in Mew's form, tries to use Mew's abilities to stop the scientist from causing more chaos.
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.
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.
Ash could become more confident and wise as a Dragon Master. His decision - making skills would improve as he deals with powerful and often unpredictable dragon Pokémon.
Often, it starts with Ash being in awe of Mew's rarity and power. Mew, seeing Ash's pure heart, decides to approach him. Then they start to trust each other more as they face challenges together, like saving a group of Pokemon from a natural disaster.
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.
No, they are not. Lemon fanfictions typically involve sexual or adult - themed content which is not in line with the family - friendly nature of the Pokémon franchise. Pokémon is aimed at a wide range of audiences, including children, and such inappropriate fanfictions go against the values it represents.