A plotline might involve Richie getting lost in an unknown region, and Ash goes to find him. Along the way, Ash meets new Pokemon and trainers. When he finally finds Richie, they both realize how much they rely on each other. This could also be a chance for Ash to show his loyalty and determination, which are some of his key traits in the Pokemon series.
Well, in some 'pokemon red and ash brothers fanfiction', a possible plotline is that they discover a hidden Pokemon world. In this world, the rules of Pokemon battles are different. They have to adapt quickly to survive. Also, they might have to solve the mystery of a powerful but cursed Pokemon that is causing chaos in their hometown. Or perhaps they get involved in a time - traveling adventure where they meet their ancestors who were also Pokemon trainers and learn valuable lessons about family and Pokemon training from them.
Ash, the protagonist of the main Pokemon series, is a central figure. He has his Pikachu by his side most of the time. Richie, who is often seen as a kind of rival or brother - like figure to Ash, is also a main character. His Pokemon, like his Butterfree, play important roles in the fanfiction. Sometimes, other characters from the Pokemon universe like Brock or Misty might also make appearances to add more depth to the story.
In a fanfiction plot, perhaps Ash and Richie are twins who were sent to different regions by their parents for some mysterious reason. As they grow up, they both become excellent Pokemon trainers. When they finally meet, they initially compete against each other. But then they realize that together they can achieve more. They might then explore ancient Pokemon ruins together, where they discover secrets about their family and the origin of some powerful Pokemon.
One possible plotline could be Ash's discovery of his own latent legendary powers. Maybe he starts to exhibit abilities that are unique to legendary Pokemon, like controlling the weather or having an extraordinary bond with all types of Pokemon.
Another plotline could be centered around a family secret that only they can uncover. This secret might be related to a special Pokémon or a hidden power. As they search for the truth, they also strengthen their brotherly relationship, facing various challenges along the way, like rival trainers who are also after the same secret.
One interesting plotline could be Ash facing a new and extremely powerful legendary Pokemon that challenges his skills as a champion in ways he's never experienced before. This could lead to him having to develop new battle strategies.
One interesting plotline could be Ash becoming a super powerful trainer overnight in the fanfiction. Maybe he discovers a new type of Pokemon power that gives him an edge in battles.
One interesting plotline could be Mallow and Ash going on a special cooking adventure where they combine their skills. Mallow's cooking knowledge and Ash's love for Pokémon could lead them to discover a new Pokémon that is attracted to Mallow's special dishes. They might then have to figure out how to catch it while also dealing with some challenges from Team Rocket who want to steal the Pokémon for themselves.
In some 'legendary pokemon and ash fanfiction', there might be a plotline where Ash travels to a hidden realm where only legendary pokemon exist. Here, he has to prove himself worthy to the legendary pokemon in order to gain their help in his journey to become a pokemon master. This could involve facing various trials and challenges that test his skills, courage, and friendship with his pokemon.
Another plotline could be Ash getting involved in some sort of virtual Pokemon world within the fanfiction that has unique rules and challenges. He could discover new Pokemon species that are exclusive to this gamer - themed world. This would add a whole new dimension to his adventures and his relationship with his existing Pokemon team as they all adapt to this new environment.