One possible storyline could be that Ash and Erika are on a journey to find a rare Pokémon that is said to have special powers. Along the way, they face various challenges like rough terrains and other trainers. Another could be that they are traveling to a Pokémon tournament together and during their travels, they help each other improve their Pokémon's skills.
Well, perhaps they start their travels because Erika wants to explore different regions to find new types of plants for her garden. Ash joins her, thinking he might find some rare Pokémon in the process. As they travel, they encounter a group of poachers. Ash and Erika team up to stop them, using their Pokémon's combined abilities. This adventure not only strengthens their bond but also gives them a new sense of purpose in their travels.
In a 'Ash travels with Erika fanfiction', they might be traveling in search of a lost Pokémon village. Erika is interested in the unique flora and fauna that might be there, while Ash is eager to meet new Pokémon. On their journey, they have to cross a large, dangerous forest. They rely on each other's knowledge - Ash's battle skills and Erika's understanding of nature - to make it through. They also meet some friendly Pokémon who guide them further on their quest.
A group of rival trainers could be the antagonists. These trainers are jealous of Ash's skills and Erika's knowledge. They constantly try to sabotage their journey, for example, by setting traps or spreading false rumors about dangerous Pokémon in the areas they are about to travel through.
One possible storyline could be Ash and his Greninja. They could go on a special mission to save a group of Pokémon from a natural disaster. Along the way, Greninja and Ash have to rely on each other's skills and instincts, strengthening their bond. Another could be Ash and his male Snorlax. Snorlax gets sick, and Ash has to find a rare herb to cure it, going through many challenges in the process.
Some could be centered around a friendship - building story. Maybe Erika helps Ash understand more about grass - type Pokémon since she is a gym leader specializing in them. They could exchange knowledge and experiences, which deepens their bond.
One possible storyline could be Ash's journey after becoming the Alola champion. He might travel to other regions to share his Alola - inspired battle strategies. Another could be him mentoring new trainers in Alola, passing on his knowledge and experiences. And perhaps he could face challenges from trainers who want to take his champion title.
In this fanfiction, a great storyline could be that May's crush on Ash actually helps her grow as a person. She becomes more confident in herself and her Pokémon training because she wants to impress Ash. There could be a moment where Ash is in danger during a battle, and May's feelings for him give her the extra motivation to step in and save him, which then leads to a deeper connection between them.
Another storyline could involve a female Lugia being in trouble because some evil Pokémon trainers are trying to capture it for its power. Ash hears about this and teams up with his friends to protect the Lugia. Along the way, they face many challenges and Ash has to use his battle skills and knowledge of Pokémon to outwit the villains.
One possible storyline could be that Ash is a knight in training and Serena is a noble lady. Ash has to prove his worth in a jousting tournament to win Serena's hand in marriage. Another could be that they are both on a quest to find a magical Pokemon that is said to have the power to save the medieval kingdom from an evil sorcerer. And a third could be that Serena is a healer and Ash is a warrior, and they team up to fight off a horde of dark - type Pokemon that are attacking the villages.
Perhaps Manaphy gets lost, and Ash and May have to search through different regions to find it. During their search, they encounter new Pokemon species and make new friends who help them in their quest. This journey could also strengthen the bond between Ash, May and Manaphy.
One possible storyline could be Serena feeling heartbroken and then deciding to focus on her own Pokemon journey independently. She might strive to become a better Pokemon trainer on her own terms, proving herself not just for Ash but for her own self - worth.
Perhaps Leaf betrays Ash because she becomes jealous of his friendship with Pikachu. She might feel like Pikachu gets all of Ash's attention and decides to side with a group that wants to separate them. This could lead to Ash having to fight not only to save Pikachu but also to win Leaf back.