Pikachu is definitely a common character. It's Ash's most loyal partner and is always by his side during his adventures. Serena is also often present. She has her own dreams and goals related to Pokemon and often travels with Ash, providing support and sometimes even competing with him.
One interesting story could be about Ash's journey in the Kalos region in a more in - depth way. For example, his encounters with different Pokemon and trainers that weren't fully explored in the anime. Another might focus on his relationship with his Pokemon in a new light, like how he trains them specifically for Kalos - style battles.
One exciting plotline could be Ash encountering a new and extremely powerful Pokemon that he has to figure out how to catch. Maybe it has unique abilities that no one has ever seen before.
You can start by looking on fanfiction websites like FanFiction.net or Archive of Our Own. These platforms have a large collection of fan - created stories, and you can simply search for 'Pokemon Ash X and Y' to find relevant fanfictions.
One idea could be Serena and Ash getting lost in a mysterious forest in the Kalos region. They have to rely on each other's skills and the Pokemon they have with them to find their way out. Along the way, they might discover a new and rare Pokemon species.
Their relationship could develop further through shared adventures. For example, if they team up to rescue a group of endangered Pokemon, they would have to rely on each other's strengths and trust each other completely. This would deepen their bond.
One possible scenario in fanfiction could be that Bonnie catches a strange illness from a new Pokemon she encounters in the Kalos region. This illness might cause her to lose her energy and enthusiasm, which are her usual traits. Her friends, Clemont and the protagonist, would then search for a cure.
I'm not sure specifically as there could be various interpretations. It might involve some dark or spooky events in the Pokemon X and Y universe, like strange disappearances of Pokemon or creepy encounters in certain areas.
One idea could be a story where Naruto is transported to the Pokemon X and Y world. He could use his ninja skills to catch Pokemon in unique ways. For example, he might use his shadow clone jutsu to surround a wild Pokemon and then throw a Poke Ball with perfect accuracy.
A plot where Shauna participates in a high - stakes Pokemon tournament. She faces off against tough opponents, and each battle teaches her something new about herself and her Pokemon. The fanfiction could focus on her mental and emotional journey during the tournament, from the nerves before the first battle to the elation of victory or the disappointment of defeat.