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's loss could lead to a change in his journey. Instead of just aiming for Pokémon battles and championships, he might focus more on self - improvement and understanding his Pokémon better. He could travel to new regions to learn different training techniques or seek out wise Pokémon trainers who can give him advice on how to avoid such losses in the future.
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.
A characteristic is the expansion of the Pokemon world around Ash. Fanfiction might introduce new regions, new Pokemon species that Ash encounters. Also, many of them play with different timelines. For instance, Ash might go back in time to correct a mistake or move forward in time to see the future of the Pokemon world. Moreover, they can show Ash's emotional side more vividly, like his struggles when he loses a battle and how he overcomes it.
Well, in an 'ash the pokemon fanfiction', it might center around Ash's growth as a Pokemon trainer. It could include him facing challenges that are different from the original series, like dealing with a powerful new villain who has a unique way of using Pokemon. It could also show Ash's relationship with his Pikachu evolving in new and interesting ways.
I'm not sure specifically what this particular 'ash pokemon ash alola blind fanfic' is about without reading it. It could potentially be a fan - created story where Ash is in the Alola region and has some sort of blindness - related plotline. It might involve his adventures in the Alola region with his Pokémon while dealing with this new handicap, like how it affects his battles or his relationships with other characters.
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 storyline is Ash having a child who inherits his passion for Pokemon. The child might start their own journey, facing challenges like Ash did, but also having unique experiences. For example, they could encounter new Pokemon species that were discovered after Ash's time. Another storyline could be the child trying to live up to Ash's legacy, which adds a lot of pressure and interesting character development.
He could have a Froakie. It's a common and cute starter in Kalos. Maybe also a Skiddo for traveling across the Kalos landscapes. And a Bunnelby would be a nice addition for its digging abilities.
If Red was Ash's father in a Pokemon fanfic, Ash might start with a Pikachu like in the original series, but it could be a special Pikachu that Red had some connection to. Maybe it was a Pikachu that Red had trained briefly or had a unique bond with.