One common theme is Serena's journey of self - discovery. In the Pokemon Sun and Moon setting, she might face new challenges that force her to learn more about herself and her capabilities as a trainer. Another theme could be her relationships, whether it's with her Pokemon, her friends in the Alola region, or her old friends from previous regions.
One great Ash and Serena fanfiction in the Pokemon Sun and Moon setting is 'A New Adventure Together'. It has a really engaging plot where Ash and Serena meet up again in the Alola region and go on a journey to discover new Pokemon. The author does a wonderful job of capturing their characters and the unique charm of the Alola region.
You can try fanfiction websites like FanFiction.net or Archive of Our Own. These platforms have a large collection of Pokemon fanfics, including those related to Serena in Pokemon Sun and Moon. Just use the search function and type in relevant keywords like 'Pokemon Sun and Moon Serena' to find what you're looking for.
Ash is a great character to pair Serena with. Their history from previous adventures adds depth to the story. They could have new adventures together in Alola, with Ash showing Serena the ropes of the Alolan Pokemon world and Serena sharing her own unique skills. Another good option is Lillie. Serena and Lillie could bond over their love for Pokemon. They could help each other grow, like Serena teaching Lillie more about Pokemon battles and Lillie introducing Serena to the unique Alolan Pokemon.
Well, one possible plot could be Serena returning to Alola to participate in a grand Pokemon tournament. She might bring along some new Pokemon she's trained in her time away. Maybe she teams up with the main character from Sun and Moon to take on the toughest opponents.
The best aspect is seeing their relationship grow. In the Pokemon Sun and Moon setting, they get to experience new things together. For example, Serena can learn about the unique Alola Pokemon and Ash can show her around. Their interactions are really sweet, like when Ash introduces Serena to his new Alola friends. It adds a new dimension to their relationship.
A great storyline could be Serena using her skills from her previous Pokemon training in new and unexpected ways in the Alola region. Maybe she uses her knowledge of battling to help train local Pokemon that are having trouble evolving or learning new moves. This could also lead to her becoming a sort of mentor to younger trainers in Alola, passing on her wisdom and experiences from her travels in other regions.
Her character could develop in terms of her relationships. When she returns, she might have to re - establish friendships. This could lead to her being more empathetic and better at communicating. She could also develop new rivalries, which would fuel her competitive spirit and drive her to become an even better Pokemon trainer.
Gladion could be a great rival for Serena. He has a very different approach to training and battling compared to her. His edgy style and his strong Pokemon like Silvally would pose a real challenge to Serena.
Well, perhaps Serena could get involved in a mystery regarding a rare and powerful Pokemon in Sun and Moon. She could team up with some local trainers to solve it. Maybe there's a hidden cave where this Pokemon is rumored to be, and along the way, she discovers new forms of Pokemon she's never seen before. This would add an element of adventure to the fanfiction.