Well, it could be about Ash experimenting with new battle strategies. For example, he might try to combine different Pokemon moves in unexpected ways. Maybe he'd experiment with training his Pokemon in unique environments like a mysterious forest filled with rare Pokemon. This could lead to his Pokemon evolving in new and exciting ways, and he could discover new Pokemon abilities along the way.
One interesting story could be about Ash being part of a secret Pokemon evolution experiment. In this fic, scientists might be trying to force-evolve Pikachu in a way that goes against nature. Ash has to fight to protect Pikachu and the bond they share. It shows his determination to keep his Pokemon's well - being a top priority.
Perhaps a powerful and mysterious trainer. This trainer is jealous of Ash's connection with his Pokemon and his ability to conduct these experiments. He wants to prove that he is the better trainer. So he tries to disrupt Ash's experiments by challenging him to battles at inconvenient times. He also spreads false rumors about Ash's experiments being dangerous to other Pokemon, which causes some local Pokemon communities to be hostile towards Ash.
You can try websites like FanFiction.net. It has a large collection of Pokemon fanfictions, and you can search specifically for ones related to Ash and Pokemon experiments. Just use the search bar and type in relevant keywords like 'pokemon experiment ash' and you'll likely find a bunch of stories.
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.
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.
The impact of Ash's loss in the fanfiction could extend beyond just himself. His Pokémon might also feel demoralized. However, this could also be an opportunity for them to grow stronger together. Ash could start training more intensively, seek new training methods, or even try to catch new Pokémon to strengthen his team.
In a fanfiction about Ash born in 1987 and his situation in 1997, we could see an alternate story where Ash is not the typical rookie trainer. Since he's a bit older than in the original, he might be more knowledgeable about Pokémon lore. He could be on a quest to uncover some ancient Pokémon secrets in 1997. He might travel to different regions, not just for battles but also to study old Pokémon texts and artifacts, and along the way, form an unusual team of Pokémon that are attracted to his in - depth knowledge.
There are also fanfictions where Ash catches Rayquaza. This could be set during a time when the sky is in chaos due to some dark energy. Rayquaza is drawn to Ash because of his pure heart and determination. Ash, with his usual courage, teams up with his pokemon to assist Rayquaza in restoring balance. As a result, Rayquaza allows Ash to catch it.
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.