A fanfiction could focus on Ash Greninja's unique form and abilities. For example, it could tell a story where Ash has to rely on Greninja's special skills to overcome a powerful, mysterious Pokemon in the Alola region. This would show the significance of their partnership in the context of Pokemon Sun and Moon.
One possible fanfiction could be where Ash has to dress as a girl for a mission in the Alola region (Sun and Moon setting). Maybe he needs to infiltrate a group that only allows girls. He would struggle at first with the new appearance but gradually get used to it and use his skills to complete the task.
One possible fanfiction could be about Ash and Lillie's adventure in the Alola region. Maybe they team up to face a powerful new Pokemon that has been causing trouble. They use their combined skills and the unique bond they've developed throughout their journey in Pokemon Sun and Moon.
One great Ash and Serena fanfiction in the Pokemon Sun and Moon setting is 'A New Adventure Together'. It has a really engaging plot where Ash and Serena meet up again in the Alola region and go on a journey to discover new Pokemon. The author does a wonderful job of capturing their characters and the unique charm of the Alola region.
One common theme is friendship. Ash forms strong bonds with his friends in the Alola region, just like in the series. For example, his relationship with his classmates is often explored more deeply in fanfics.
One interesting fanfiction could be about Ash's adventures in the Alola region where he discovers a rare and powerful Pokemon that isn't in the main series. It could show his journey to train it and how it changes his relationship with his other Pokemon.
In the world of Ash and Serena Sun and Moon fanfictions, 'Alola's Destiny' stands out. This fanfiction dives deep into how Ash and Serena's paths cross again in the Alola region. It not only shows their individual growth but also how their relationship evolves. The detailed descriptions of the Alola region and its Pokémon add to the charm. 'Serena's Sun and Ash's Moon' is another interesting one. It plays with the idea of their different experiences in the Alola region, Serena being more in tune with the sun - related aspects and Ash with the moon - related ones, and how they come together through it all.
One common theme is Ash's growth as a trainer. In the Alola region of 'pokemon sun and moon', Ash faces new challenges and his experiences shape him into an even better trainer. Another theme is friendship. He forms new friendships with both people and Pokémon in Alola. For example, his relationship with his new Pokémon like Rowlet, Litten and Popplio is often explored in these fanfics.
In some fanfictions, Ash Greninja's moment of saving Ash from a dangerous fall during a battle in the Alola region is really cool. It shows their loyalty and quick reflexes.
Lillie is also a main character. She has her own story arc, especially regarding her relationship with Pokemon and her growth from being initially afraid of them to becoming more confident. And her family's secrets might also play a role in the fanfic.