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.
Pikachu is the obvious one. It has been with Ash through thick and thin. It would be heartbroken and might not function well without Ash. But also, all the starter Pokemon Ash had over the years like Bulbasaur, Charmander (now Charizard), and Squirtle would be deeply affected. They looked up to Ash as their leader and friend, and his death would leave a big void in their lives.
Definitely Pikachu, as it was Ash's first and most beloved Pokemon. But we can't forget about the other Pokemon that Ash had a special connection with, like Greninja. Greninja was a powerful ally to Ash, and his death would be a big blow to it. And then there are the Pokemon that Ash helped and protected during his travels, like the wild Pokemon in different regions. They would also feel the impact of his death as he was like a hero to them.
Well, his death would likely cause great sadness among the Pokemon. They've formed strong bonds with Ash. Some might become withdrawn or less trusting of humans. The Pokemon he protected would probably feel a deep sense of loss and guilt, as if they should have been able to prevent it.
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.
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.
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.
Their closest friends like Brock and Misty would surely be affected. They've been through so much with Ash, and his betrayal would be a huge shock. And for Lyra, her friends in her own region might be deeply hurt.
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 some fanfictions, Ash gets angry. He might be angry at the world, at fate, for taking his mom away. This anger could manifest in different ways, like being more reckless in battles or snapping at his friends when they try to comfort him. But deep down, it's just his way of dealing with the overwhelming pain of losing his mother.
His Pokémon, like Pikachu, would surely be important characters. Pikachu might be the first to suspect that Ash is not really dead and start searching for him. Misty and Brock could also be main characters. They are Ash's long - time friends and would be deeply affected by his supposed death. They might be the ones to uncover the truth behind his faked death and help him in his plan, or they could be completely in the dark at first and then gradually figure things out.
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.
Obviously, Ash is one of the main characters. Since it's about him being a legendary Pokemon in this fanfiction, he's central to the story.