One common theme is growth. Just like in the original series, Ash starts as a novice trainer. In fanfictions, his journey of growing in terms of battle skills, knowledge about Pokemon, and emotional maturity is often explored. Another theme could be friendship. He meets various characters along the way, and their relationships are developed. For example, his bond with Pikachu might be deepened in different and interesting ways in the fanfiction.
One popular original character added in some fanfictions is a young trainer who becomes Ash's rival. This character often has a unique backstory and a different approach to Pokemon training compared to Ash. For example, they might focus more on the scientific aspect of Pokemon abilities.
Ash could face some tough challenges in this fanfiction. He might have to train in harsh conditions to become a champion. For instance, training on a snowy mountain where Pokemon are stronger due to the environment. His team would need to adapt and grow. Maybe he gets a new Pokemon that is a bit of a troublemaker at first but later becomes a key player in his battles.
It could slow him down. Ash might be so distraught that he doesn't focus well on training his Pokemon. His usual enthusiasm for battles and catching new Pokemon might wane, as his mind is preoccupied with his broken heart.
One common theme is friendship. Ash's relationships with his Pokemon and other trainers are often explored deeply. For example, how he bonds with new Pokemon he catches or how he helps his friends in tough situations.
In his regular trainer journey, Ash travels from one gym to another, challenging strong opponents to prove his strength. When he becomes a coordinator, he travels to different contest halls. His opponents are not just about raw power but also about creativity. He has to choreograph his Pokemon's moves in a way that tells a story or shows off their best features. Also, in trainer battles, strategies are more about type advantages and battle tactics, but in contests, it's about impressing the judges with unique combinations of moves and Pokemon's expressions.
If we consider the common growth pattern in the Pokemon series, Charmander evolving into Charmeleon could be an early evolution in the fanfiction. Since Charmander has a clear evolution line and Ash has a strong bond with it, it would make sense for it to be one of the first to evolve, perhaps due to a tough battle or a special encounter that accelerates its growth.
One idea could be that Ash discovers a Sylveon in a forest. The Sylveon is injured and Ash takes it upon himself to nurse it back to health. This could lead to a strong bond between them, and Sylveon could become a unique addition to his Pokémon team, with new adventures and battles ensuing.
One plot might involve Ash and Cynthia being invited to a mysterious Pokemon tournament. But as they enter, they realize it's a trap set by an evil organization. They then have to fight their way out while also trying to expose the organization's evil plans.