A good fanfic of their reunion should have a strong emotional connection. Show Ash's excitement and Greninja's loyalty. Also, a great plot like a new threat they must face together.
They might have an epic battle against a common enemy together. Greninja could show off some new moves it has learned during their separation, and Ash could use his experience from other adventures to lead them to victory.
There could be unfinished business between them. They might have a shared goal that they haven't achieved yet. Greninja's return to Ash in the fanfiction could be to finally complete that goal, whether it's winning a particular Pokemon tournament or saving a certain place from destruction.
One popular 'ash and greninja fanfic' might be those where they face an extremely powerful and rare Pokemon together. In these stories, Greninja's unique abilities combined with Ash's leadership and battle strategies create exciting adventures. For example, they could be on a quest to save a region from a mysterious dark force. Greninja's water - type attacks and its transformation capabilities play a crucial role in the battles, while Ash's bond with his Pokemon gives them an edge.
You can start by looking on fanfiction websites such as FanFiction.net or Archive of Our Own (AO3). These platforms have a wide variety of fan - created content, including many 'ash and greninja fanfic'. Just use the search function on the site and type in 'ash and greninja' to see the available stories.
Well, they could have an epic battle side by side again. Maybe they face a powerful new enemy that only their combined skills can defeat. Ash could show how much he's grown since they last parted, and Greninja might have some new moves or abilities too.
Another theme is the exploration of the unique Alola environment. Fanfics may describe how Ash and Greninja interact with the new Pokemon species and the local culture in Alola. It can also involve Ash using Greninja in Alola - specific battles and tournaments, showing off their new strategies and teamwork.
One popular Ash and Ash - Greninja fanfiction could be those that focus on their adventures in a new, unexplored region. In these stories, they might face unique and powerful Pokémon, strengthening their bond along the way.
Well, in Alola, the battle environment is different. Ash Greninja has to adapt to the new battle rules like Z - Moves. It may start by observing local battles and learning from them. It could also adapt to the more friendly and less intense battle atmosphere compared to other regions. This means it might have to change its battle strategy a bit, not always going all - out from the start. And it might interact with different types of Pokemon that are native to Alola, which could lead to new friendships or rivalries, further shaping its adaptation to the Alola environment.