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.
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.
You can start by looking on fanfiction websites like FanFiction.net or Archive of Our Own. They usually have a wide selection of Greninja - related fanfictions from Pokemon Sun and Moon. Just use the search bar and type in 'Greninja Pokemon Sun and Moon' and you'll get a bunch of results.
A good Greninja fanfiction in the Pokemon Sun and Moon universe often has well - developed characters. Greninja itself should have a distinct personality, not just be a copy of what we see in the games. The author should give it more depth, like its thoughts, feelings, and relationships with other characters.
The best aspect is seeing their relationship grow. In the Pokemon Sun and Moon setting, they get to experience new things together. For example, Serena can learn about the unique Alola Pokemon and Ash can show her around. Their interactions are really sweet, like when Ash introduces Serena to his new Alola friends. It adds a new dimension to their relationship.
A new Team Rocket - like organization could be the main antagonist. They might be after Greninja because of its unique abilities. They could try to capture Greninja to use its power for their own evil purposes, like taking over the Alola region.
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.
Obviously, Greninja is one of the main characters as the title suggests its return. The trainer who was associated with Greninja before would also be a main character. They are likely to be central to the story's development.
One idea could be that Greninja returns with a new power that it gained during its time away. It could use this power to help Ash in a crucial battle in the Alola region. For example, it might have learned to control water in a more unique way, like creating ice sculptures that can attack opponents.
In many such fanfictions, the plot might involve Ash's friends suddenly turning against him due to some false accusations or misunderstandings. For example, they could believe that Ash has been secretly working with an enemy group, which leads to his betrayal.