One popular theme is the growth of Ash's relationships with the different characters in his harem. It often shows how they support him in his Pokemon journey. Another theme could be the unique dynamics between Ash and each member of the harem, like how they interact during battles or in different regions.
Misty is often in Ash's harem in fanfictions. She has been with Ash since the beginning of his journey and their relationship has a long history. Another common one is Serena. She has strong feelings for Ash and her character development is closely tied to him.
Some popular ones might include those that explore different relationships Ash could have with his female companions in unique storylines. For example, fics where his bond with Misty takes on a more romantic angle in a different adventure setting.
In many fanfictions, Ash achieving the status of a Pokemon Master often involves him having extraordinary battles. He might defeat powerful legendary Pokemon that no one has ever tamed before. His Pikachu could evolve into a more powerful form, which gives him an edge in battles. Also, his bond with all his Pokemon, not just Pikachu, becomes so strong that they can execute complex strategies without any communication barriers.
One idea could be that Ash discovers a hidden power within himself that allows him to communicate directly with Legendary Pokemon. This power sets him on a journey to understand the secrets of the Legendary Pokemon world. He might start by having an encounter with Mew, who guides him to different places where he can learn more about his new ability.
In some Pokemon fanfictions, there could be creative interpretations where Ash is made out to be Red's father. However, in the official Pokemon canon, there is no such relationship between them.
Typically, through shared Pokemon - related experiences. For example, when Ash and his female companions train their Pokemon together or go on adventures to catch new ones.
A common theme in such fanfictions could be Ash's adventures in Alola while building relationships with different characters. Maybe he forms special bonds with his Pokémon and the people around him in a more romantic or friendship - deepening way.
One popular story could be 'Ash's Unusual Adventures in the Harem World'. In this, Ash might find himself in a world where he has to deal with multiple female companions in unexpected ways. Another could be 'Ash and the Harem of Pokémon Trainers', where female trainers from different regions are all attracted to Ash's unique charm and skills.
One common theme is friendship. Ash forms friendships with the female characters in Alola that gradually develop into something more like a harem. Another theme is growth. Ash grows not just as a Pokemon trainer but also in his relationships as he navigates this new dynamic.