Maybe Serena goes to Alola to study the different forms of Pokemon there. She teams up with some local trainers and discovers secrets about certain Pokemon's evolutions. Along the way, she has friendly battles and exchanges training tips with others, all while exploring the beautiful Alola islands.
One possible plot idea could be Serena starting a new Pokemon journey in Alola. She might encounter unique Alola Pokemon and have to adapt to the new region's battle styles. For example, she could participate in the Alola trials and learn about the local culture and traditions related to Pokemon.
A Litten might be a good choice for Serena. It has a fiery personality and could bring a new dynamic to her team. With proper training, it could become a powerful Fire - type Pokemon in battles against water - type opponents in Alola.
Perhaps in the fanfiction, Ash and Serena could stumble upon a mysterious Alola Pokémon that is said to have the power to grant wishes. They then go on an adventure to find this Pokémon, while also exploring the beautiful and diverse regions of Alola. During their journey, they help local Pokémon trainers with their problems and learn more about the Alola culture.
A great plot could involve a group of friends in Alola who enter a Pokemon tournament with their underdog team. They face tough opponents but through their bond with their Pokemon and some clever strategies, they start to make a name for themselves in the tournament. Along the way, they also learn more about the different Alola Pokemon species and their habitats.
In this kind of fanfiction, they might have new adventures. They could explore the unique Alola region together, encounter new Pokemon species, and bond even more deeply. Maybe Serena would learn new battle strategies from Ash, and they would participate in local Alola Pokemon contests and battles side by side.
One possible plot could be Serena discovers she's pregnant during her Pokemon journey. This could bring about a lot of changes in her goals and how she interacts with her Pokemon. Maybe she has to take a break from her usual adventures to take care of herself and the upcoming baby, and her Pokemon become more protective of her.
The plot could involve Serena encountering a Hypno in the wild. Maybe she's initially scared, but then realizes Hypno has some unique abilities that can help her in her Pokemon journey. For example, Hypno could use its psychic powers to lead Serena to rare Pokemon or hidden items.
Well, it could start with Ash finally realizing his true feelings for Serena. Maybe they meet up again after a long time apart. Then they start to plan a small, intimate wedding in a beautiful Pokemon - filled location like a meadow full of Pikachu and Eevee. Their Pokemon friends could help with the preparations, like Pidgey delivering invitations.
She could have a team including Alolan Vulpix. It's a very cute and powerful Pokemon in the Alola region. Also, Alolan Raichu would be a great addition, with its unique surfing ability.
One idea could be a story about a trainer who discovers a rare and powerful Alola Pokemon that has been lost for centuries. This Pokemon could have unique abilities that no one has ever seen before, and the trainer has to figure out how to train it while also protecting it from those who would use it for evil.
In a fanfic, they could discover a rare and powerful Pokemon that has the ability to make wishes come true. However, this Pokemon is being hunted by an evil organization. Calem and Serena team up to protect the Pokemon. During their adventure, they share many tender moments, which deepen their love. For example, they might have to spend a night in a cold cave and huddle together for warmth, and in that moment, they confess their true feelings.