ash reunites with his old pokemon

In some fanfictions, Ash reunites with a Pokémon he had to release in the past. For instance, he might reunite with Butterfree. The reunion could be filled with nostalgia as they recall their past times together. Also, there are fanfictions where Ash reunites with his father in a very unexpected manner. This reunion often changes the course of his journey and gives him new perspectives on his life as a Pokémon trainer. Fanfictions like these explore different relationships and how reunions can be a turning point in Ash's life.

One idea could be that Ash reunites with his old Pokémon team in a completely new and mysterious region. They have to face a powerful new villain together. Another could be Ash reuniting with an old friend from his journey who has a new and rare Pokémon that they all need to protect.

Obviously, Ash and Pikachu are the main ones. But we could also see Misty and Brock, Ash's old friends from the beginning of his journey. Maybe Gary too, as he has been Ash's rival for a long time.

It could be Pikachu. Since Pikachu has been with Ash from the very beginning and is his most iconic Pokémon. It's very likely that in Sinnoh fanfiction, Pikachu would be frequently used as it has a strong bond with Ash and is also very powerful.

Perhaps there is a threat to Sinnoh that only Ash's old Pokémon can help solve. Some kind of ancient evil that has knowledge of Ash's past Pokémon battles. Ash and his old Pokémon then have to work together to defeat this threat. They might need to combine their old strategies with new ones they learn in Sinnoh to succeed. And along the way, Ash might meet some of his old friends who are also in Sinnoh and they help him in his mission.

If we consider the common growth pattern in the Pokemon series, Charmander evolving into Charmeleon could be an early evolution in the fanfiction. Since Charmander has a clear evolution line and Ash has a strong bond with it, it would make sense for it to be one of the first to evolve, perhaps due to a tough battle or a special encounter that accelerates its growth.

Maybe Tracey. He was also an acquaintance of Ash. Since Tracey has his own unique skills and knowledge about Pokemon, his presence could bring new elements to the story. He could help Ash and other friends with things like Pokemon research or understanding some rare Pokemon behaviors.

In fanfiction, Ash might improve his pokemon's IV through special training regimens. For example, he could focus on specific battle scenarios that target areas related to IV stats like speed or strength. He might also seek out rare items in the fanfiction world that have the power to enhance these inherent values.

One idea could be that Ash discovers a Sylveon in a forest. The Sylveon is injured and Ash takes it upon himself to nurse it back to health. This could lead to a strong bond between them, and Sylveon could become a unique addition to his Pokémon team, with new adventures and battles ensuing.

Well, it could mean that Ash is getting inspiration from the creativity in those old fanfics. Maybe he finds unique storylines or character interpretations that he can use in his own Pokemon journey, like new strategies or ways of bonding with his Pokemon.