One common plot is that Ash discovers a hidden egg of a legendary starter Pokémon. He then has to protect it from poachers or other trainers who want to use its power for evil. Another plot is when Ash is chosen by a legendary starter Pokémon to be its partner to save the Pokémon world from a great threat.
In many fanfictions, there's a plot where a legendary starter Pokémon is in trouble, and Ash is the only one who can help. Maybe it's been poisoned or trapped by some dark magic. Ash has to use his wits and the help of his friends to rescue it. This plot often leads to Ash forming a strong bond with the legendary starter. Another common plot is that Ash accidentally stumbles upon a time - traveling device that takes him to an era when legendary starter Pokémon were more common. He has to find his way back while also learning about the origins of these powerful Pokémon.
Well, in many fanfictions about Ash and legendary starter Pokémon, the writers often give Ash a unique bond with these Pokémon. It could be that he has to save a legendary starter from an evil organization. This not only tests his skills as a trainer but also his moral compass. He might learn new techniques or gain access to special areas in the Pokémon world because of this connection. It's a great way to expand on the original Pokémon story and give Ash more depth as a character.
One common theme is growth. Ash and his starter often go through significant character growth as they face different challenges. For example, they might learn important lessons about friendship and perseverance.
Mewtwo is also a common Legendary Pokémon in Ash - related fanfiction. Mewtwo's complex personality and its powerful psychic abilities make for interesting interactions with Ash. There can be stories about Mewtwo respecting Ash's bond with his Pokémon and joining him on a journey, or even testing Ash's worthiness.
Some fanfictions focus on Ash's relationships with other trainers in the context of being a legendary trainer. He could form alliances with other powerful trainers, and together they face challenges like tournaments where the stakes are not just victory, but also the fate of the Pokémon world.
One possible plot could be that Ash discovers a special Shinx that has a rare ability. This leads him on a quest to find out more about this ability and how to help Shinx develop it further. Along the way, he might encounter trainers who are also interested in Shinx's unique ability and try to steal it or challenge Ash for it.
I'm not sure specifically as there could be many different interpretations. It might be about Ash from the Pokémon world having a Pokémon that is considered a pseudo - legendary as his starter Pokémon. Maybe it details his adventures with this special starter in a unique and creative way that diverges from the normal Pokémon storylines.
One great fanfiction about Ash as a legendary Pokémon trainer could involve him traveling to a new, mysterious region filled with rare and powerful Pokémon. He might start with his Pikachu, of course, and gradually build a team of Pokémon that are not only strong but also have unique abilities.
Another plot is that Ash dresses as a girl as part of a bet or a challenge. Throughout the fanfiction, he discovers new aspects of himself or the Pokemon world that he wouldn't have otherwise. For example, he might learn about the unique challenges female trainers face.
One interesting plot could be where the starter pokemon, say a Charmander that is a legendary type in this fanfiction, has to go on a quest to save its kind from an evil force that wants to use their power. It might face many challenges and make new friends along the way.
One common theme is sacrifice. Ash might have to sacrifice his own goals or dreams temporarily to fulfill his life debt. For example, he may give up a chance to compete in a big Pokémon tournament to help the Legendary Pokémon in need.