Pikachu is often used. Since Pikachu is one of the most well - known and beloved Pokemon, it's a natural choice. In reverse harem scenarios, a Pikachu might be very protective of the female character and show its affection in cute ways like cuddling or bringing her berries.
Eevee is often seen in 'pokemon characters react fanfiction' too. Because it has so many different evolutions, there are many possibilities for reactions. It could react to meeting another Eevee with a different evolution path, or to a situation that might trigger one of its evolutions.
Ash is of course a very common character as he is the central figure. Pikachu is also often included as it is Ash's most well - known Pokémon. Other characters like Misty and Brock might also make appearances as they are Ash's friends and travel companions in the original Pokémon series.
Eevee is also common. With its various evolutions, it can add a lot of variety to the harem dynamic. Different Eeveelutions might represent different personalities within the harem, and the idea of an Eevee evolving based on its relationship with the trainer can be an interesting plot point.
One of the common pairs is Dawn and Piplup. Their journey together in the anime can be the basis for a romantic story in fanfiction. The loyalty and closeness they showed in the show can be developed into a love story. Then there's Gary and his Eevee. Since Gary is a popular character, writers often explore a romantic relationship between him and his Eevee, perhaps with Eevee evolving into a form that is more compatible with a human - like relationship. And Brock and Onix have also been paired in some fanfictions, taking their trainer - Pokemon relationship to a different level.
Ash is obviously one of the main characters. He is at the center of the harem concept. Then there would likely be a group of human characters who are part of his harem, though their specific identities can vary greatly depending on the fanfiction.
Sylveon is a very charming Pokemon. In a harem scenario, it could be the Pokemon that brings harmony to the group with its fairy - type nature. And then there's Lucario. It's strong, intelligent, and has a sense of honor. It could play the role of the protector in the harem, making sure all the other Pokemon are safe while also having a special bond with the trainer.
One common plotline is a female trainer finding herself in a situation where multiple male Pokemon characters are attracted to her. For example, she might be on a journey and these Pokemon, in their human - like forms, start competing for her attention. They could offer her help in battles or with finding rare items in exchange for her company.
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.
Often, the male reader himself is a central character. But in terms of female characters, Misty from the original series is quite popular. Her feisty personality and love for water - type pokemon make her an interesting addition to the harem. Another popular character could be Serena, with her kind heart and determination in her pokemon journey. She can bring a lot of emotional depth to the harem dynamic.
Ash is obviously the central character. Then there are the female characters from the Alola region that often form his harem. Lillie is a very common one. She has a gentle and kind personality and her relationship with Ash can be explored in many ways in the fanfictions. Another is Mallow. Her love for cooking and her energetic nature make her an interesting character to include in the harem. And there's also Lana, with her love for water - type Pokemon.