A great plotline might involve Ash's journey to discover why he can only catch shiny pokemon. Maybe it has something to do with a long - forgotten prophecy or a special power within him. Also, his relationships with his shiny pokemon could be explored deeply. For example, how they communicate differently compared to normal pokemon. This could lead to some heart - warming and exciting moments in the fanfiction.
One interesting plot could be that Ash catches a shiny Pikachu which has some unique powers, like being able to communicate telepathically with other Pokemon. This would change the way Ash interacts with his team and the challenges he faces in battles.
One possible plot could be that Ash stumbles upon the shiny pokemon by pure chance while exploring a new, uncharted area. Maybe he's looking for a specific type of pokemon for a local competition and instead, he discovers this rare shiny pokemon. Another plot could involve the shiny pokemon being in danger from a group of poachers, and Ash has to rescue it. Then, after rescuing it, he forms a special bond with the shiny pokemon which is different from his bonds with his other pokemon.
A self - proclaimed 'collector' of rare pokemon could be a rival. This person has a huge collection of non - shiny but very rare pokemon and sees Ash's shiny pokemon as the ultimate addition to their collection. They would stop at nothing to get their hands on at least one of Ash's shiny pokemon. And of course, there could be other trainers who simply can't stand the fact that Ash has such an amazing ability and they don't.
One possible plotline could be that Ash has to overcome his own self - doubt. He might initially think he's not worthy of catching a legendary pokemon. But through his journey, he discovers his hidden strengths and forms a deep bond with the legendary pokemon. For example, he could learn that his pure heart and unwavering determination are what attract the legendary pokemon to him.
Obviously, Ash is one of the main characters. He is the trainer who catches the shiny Pokemon. His Pikachu also plays a significant role, as it's always by Ash's side and could potentially have some interesting interactions with the shiny Pokemon.
There could be a new, evil organization in the fanfiction. Their goal is to use shiny pokemon to power some sort of dark machine or experiment. They target Ash's shiny pokemon because it has a particularly strong energy. This organization would send out their minions to attack Ash and try to capture the shiny pokemon, creating a lot of action - packed scenes in the story.
One possible plotline could be that Ash catches the Giant Dragonite and has to train it to control its immense power. Maybe it has a special ability that no other Dragonite has, and Ash has to figure out how to utilize it in battles. Another could be that the Giant Dragonite has a past connection to a legendary Pokémon, and as Ash catches it, he gets involved in an ancient mystery related to that legend.
There's a fanfic called 'Ash's Mastery of Pokemon Catching'. It shows Ash using unique strategies to catch different types of Pokemon. For example, he uses his knowledge of Pokemon behavior to outwit them. Also, 'The Golden Pokeball Adventure of Ash' is an interesting one. Ash finds a special Pokeball that has unique powers for catching Pokemon, which leads to a series of thrilling events.
In many Pokemon fanfictions where Ash catches Machop, it often shows Ash's growth as a trainer. Maybe he discovers Machop in a unique situation, like in a hidden valley. Machop is a strong and determined Pokemon, so when Ash catches it, it could potentially become one of his most powerful allies. It might be a story full of adventure and challenges as Ash tries to train Machop and bond with it.
One possible scenario in this fanfiction could be that Ash encounters Mewtwo in a new, uncharted region. Mewtwo, being intrigued by Ash's unwavering spirit, decides to test him. Ash passes the tests with the help of his Pikachu and other Pokemon. This leads to Mewtwo seeing Ash as a worthy trainer and allowing itself to be caught. It would be a great twist on the usual Pokemon-catching storylines.