On a more positive note, his death could inspire other trainers to be more like him. Young trainers might see his selfless sacrifice and be motivated to become better, more ethical trainers. They could strive to form deeper bonds with their Pokémon, just as Ash did, in his memory.
The Pokémon world in the fanfiction could be thrown into chaos. Ash was known as a great trainer and his presence had a certain influence on the balance of power. With his death, other trainers might start scrambling for power or resources, thinking there's a void to be filled. Also, the regions he visited might experience a decline in tourism as many trainers and fans were attracted by Ash's adventures there.
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.
In the fanfiction, not being able to touch Pokemon would isolate Ash in a way. He couldn't participate in activities like grooming or training that require physical contact. This could make other trainers view him as an outcast, and he'd have to work extra hard to prove his worth as a trainer without the use of physical touch.
One reason could be a powerful and evil Pokémon that he couldn't defeat. Maybe he encounters a super - strong legendary Pokémon that has been corrupted or is in a rage and it ends up fatally injuring him. Another possibility is that he sacrifices himself to save his friends or his Pokémon. For example, he might put himself in harm's way to protect Pikachu from a dangerous situation.
Well, perhaps in the fanfiction, Ash fakes his death to escape from some sort of unwanted fame or pressure. He's been in the spotlight for so long, and he just wants a break. So, he devises a plan to make it seem like he's passed away. Then he could start a new life in a different region, maybe with a new identity, and train Pokémon in a more peaceful and private way. He could also use this opportunity to learn more about some rare and elusive Pokémon without the media or his fans constantly following him.
One consequence could be that Ash loses his human identity to some extent. His friends might not recognize him at first, and he would have to figure out how to communicate that he is still Ash inside. Also, his Pokémon might be confused about their trainer's new form.
One consequence could be that he might avoid any events or communities related to Pokemon fanfiction. He won't be interested in interacting with fans who are into it, which could create a bit of a divide between him and some parts of the Pokemon fan community.
One common theme is sacrifice. Ash might sacrifice himself to protect his Pokemon or the Pokemon world. Another theme could be the idea of mortality in a world that is usually quite fantastical and where the main character is seen as invincible in the official series. Also, some fanfictions might explore the reactions of his friends and Pokemon to his death, which can be a very emotional theme.
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.
One consequence could be a stronger bond in battles. They might team up more often against tough opponents.
Pikachu would be one of the most affected. It was Ash's closest partner. It would likely be in deep grief and might even lose its usual energetic and happy - go - lucky nature. Charizard could also be greatly affected as it had a strong bond with Ash. It might become more aggressive or reclusive.