ash uses old pokemon fanfiction

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.

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.

Maybe Ash's old Pokémon have unique skills that are rare in Kalos. So, he uses them to gain an advantage in Pokémon contests or battles. His Charizard, for instance, could be a formidable opponent against Kalos's dragon - type Pokémon, and this could lead to some exciting rivalries and plot twists.

Typically, his old team could include Pikachu, of course. Then there might be Charizard, Bulbasaur, Squirtle, and others like Greninja. These Pokémon have been with Ash through different adventures in various regions.

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.

Pikachu is a very likely candidate. It's Ash's most iconic Pokemon and has a deep bond with him. Whenever Ash is in trouble, Pikachu often steps up to protect him.

Well, it could be that Ash and his old friends meet up at a Pokemon tournament. There, they share stories of how their Pokemon have grown and evolved since they last saw each other. They might also team up to compete against a group of tough trainers, showing off their combined skills and the strong bond they have.

Ash could be a Pokémon trainer with a different starting point in this fanfiction. Born in 1987, by 1997 he might have already made a name for himself in local Pokémon battles. He could have a team of Pokémon that he rescued from difficult situations, like a Charmander that was abandoned by its trainer. His story could revolve around giving these Pokémon a second chance and proving that Pokémon don't need to be 'perfect' to be strong.

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.

It could be for nostalgia. Ash has a long history with his Pokémon, and using the old ones in a Unova fanfic might be a way to bring back memories for the readers who have followed his journey from the start. It also shows his growth as a trainer, as he can rely on the skills and bonds he's developed with his older Pokémon in a new region.