I'm not sure of a specific one off - hand, but you can try looking on fanfiction - specific websites. There are often tags for 'Pokemon Ash' and 'blue eyes' that can help you narrow down your search.
Some fanfictions might explore the idea of Ash having blue eyes in an alternate universe. In this universe, the rules of Pokemon training are different because of his distinct appearance. His blue eyes could attract different kinds of Pokemon that are not common in the normal Pokemon world, and he has to learn new strategies to train and battle with them.
It could be a fan - made story about Pokemon where Ash has a blue aura. Maybe it involves Ash having some special powers or abilities related to this blue aura in the context of the Pokemon world.
In a 'pokemon red and blue meets ash' fanfiction, Ash could face some challenges related to the game's story. For example, he might get involved in the conflict between Team Rocket and the Pokemon League. His Pikachu would surely be a key player in battles against the strong Pokemon in the game world. He might also discover new things about Pokemon evolution and training methods that are different from what he already knows.
I'm not able to directly recommend a particular 'pokemon ash blue aura fanfiction'. However, you could look for it on popular fanfiction platforms. Check the reviews and ratings on those sites to find well - received ones. Also, you can join Pokemon fan communities and ask for recommendations there.
Team Rocket would be a likely main villain. They are a big part of the Pokemon Red and Blue story, and when Ash enters this world, they would surely cause trouble for him. Their schemes to steal Pokemon and take over the world would be a direct threat to Ash and his new friends.
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.
One popular type of Pokemon Ash and Pikachu fanfiction might be adventure - based. For example, Ash and Pikachu could embark on a journey to a new and mysterious region filled with undiscovered Pokemon species. They might face challenges like difficult terrains and powerful, previously - unseen Pokemon. In this fanfiction, Pikachu's electric powers could be enhanced in some unique way, and Ash would have to strategize differently to overcome the obstacles.