Obviously, Ash is the most important character as the story revolves around his death and return. Pikachu is also crucial as his closest pokemon companion. His friends like Misty, Brock, and Serena would play significant roles as they would be affected by his death and overjoyed at his return.
In such a fanfiction, a common plot point could be the shock and grief among Ash's friends when he dies. Maybe Pikachu refuses to leave his side at first. When he returns, he might have some new powers or a different perspective on his pokemon journey.
In certain fanfictions, Ash might die from an incurable disease that he contracts while exploring a new and mysterious region in the Pokémon world. His Pokémon then have to deal with his loss and some might go on a journey to find a way to bring him back. For example, Pikachu could be determined to find a mythical Pokémon that has the power to revive the dead.
In fanfiction, if Ash were to die in Pokemon XYZ, it would be a huge shock to the Pokemon world. His friends like Pikachu would be devastated. Maybe Team Rocket would even feel a strange sense of loss. It could lead to a whole new storyline where his friends try to avenge his death or carry on his legacy of becoming a Pokemon Master.
There could be. Fanfiction is a very creative and diverse medium. Writers can take the Pokemon XY setting and create all kinds of scenarios, including ones where Ash meets an untimely end. But it might not be a common type of fanfiction because Ash is such an iconic and beloved character. His death would be a very drastic departure from the normal upbeat and adventure - filled Pokemon stories.
Ash would be extremely heartbroken. He might cry a lot and be in a state of shock at first. Then he would probably feel angry at the situation that led to Gary's death, whether it was a villain or just a dangerous accident. Ash would also feel a strong sense of responsibility, as if he has to carry on Gary's unfulfilled dreams.
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.
There are also fans who might be a bit angry or disappointed. They see Ash as a symbol of hope and perseverance in the Pokémon world, and having him die in a fanfiction goes against what they expect from the character. However, they also understand that it's part of the creative freedom in fanfiction writing.
One common theme could be redemption. Paul, who may have been a rival or even a bit of an antagonist at times, redeems himself through his selfless act of dying for Ash. Another theme might be friendship. It shows that even in the Pokemon world, where competition is high, deep friendships can form. And finally, heroism. Paul becomes a hero in his sacrifice for Ash.
The other trainers in Pallet Town might look up to him even more now. They could gather around him, asking for stories about his battles and the rare Pokémon he's encountered. It would be a great opportunity for Ash to pass on his experience.