By giving him new goals. Instead of just winning badges, he could aim to understand the origin of all Pokemon species. This would lead him to explore ancient ruins and talk to Pokemon scholars.
His backstory could be explored more. For example, we could learn about how he got interested in ghost - type Pokemon in the first place. Maybe he had an encounter with a kind - hearted ghost - type when he was young that inspired him.
Mewtwo's character can be developed further by exploring its emotions more deeply. For example, showing its fear of being alone or its longing for a true family. Fanfiction can also focus on Mewtwo's moral struggles, like whether it should use its powers for revenge or for good.
To develop their characters further, a fanfiction could put them in a situation where they have to save a group of endangered Pokemon. Ash's impulsive nature and Burgundy's more calculated approach could either clash or complement each other. Through this experience, they both learn to adapt and grow. Ash might become more patient, and Burgundy might become more open - minded, which would enhance their individual characters and their relationship.
For Ash, his character could be developed further by showing his growth in understanding different Pokemon cultures. With Molly, he could learn new ways of interacting with Pokemon that are different from what he's used to. For example, if Molly has a closer bond with water - type Pokemon due to her origin, Ash could learn from her how to better communicate with them.
Greta could be developed by exploring her backstory more. Maybe she has a special reason for being so passionate about fighting - type Pokemon. Also, her interactions with Ash could lead to her becoming more open - minded about other Pokemon types. She might start to incorporate different strategies that Ash uses into her own battling style.
Their relationship can be developed further if they face a life - threatening situation together. For example, being trapped in a collapsing cave. Ash has to rely on Bayleef's strength and Bayleef has to trust Ash's leadership to get out. Another way is through training for a really tough Pokémon battle. They learn to communicate better during the training sessions.
One way to develop their characters further is through a story arc where they are separated from their Pokemon for a while. Ash, who is so used to having his Pokemon by his side, would have to rely on his own wits and survival skills. He might discover new strengths within himself. Lily, too, would be in a similar situation. When they reunite, they could share their experiences and have a newfound respect for each other. Also, they could get involved in a diplomatic mission in the Pokemon world, representing different regions. This would require them to be more diplomatic and understanding of different cultures, which would add new layers to their characters.
For Ash, he could be developed further by showing his growth in understanding the more delicate and nurturing aspects of Pokemon care from Erika. Maybe he starts to learn about different types of Pokemon food and habitats that Erika is an expert in. For Erika, she could be shown to become more adventurous like Ash, willing to step out of her comfort zone of her garden. For example, she could join Ash on one of his more daring quests.
For Ash, he could develop further by learning some of Domino's more strategic ways of battling. This would make him a more well - rounded trainer. Domino, on the other hand, could learn from Ash's unwavering determination and bond with his Pokemon.
For Ash, his character could be developed further by showing his growth in understanding different Pokemon cultures. Hapu could help with that as she has deep knowledge of her own region's Pokemon. For example, Ash could learn about unique training methods from Hapu.