When writing Froakie and Fennekin's characters, it's important to consider their evolutionary lines. Froakie evolves into Frogadier and then Greninja. So you can hint at its potential for growth and development in your fanfiction. Maybe Froakie has a hidden strength that it discovers during its adventures with Fennekin. Fennekin, which evolves into Braixen and then Delphox, can be written as having an inquisitive nature from the start. It might be constantly looking for ways to improve its fire - based skills. For both, use their species characteristics. Froakie's water - jumping ability can be used in action scenes, and Fennekin's ability to manipulate small flames can add drama to the story.
A good story idea could be that Froakie and Fennekin become friends during a Pokemon tournament. They start off as rivals but soon realize they have more in common. They then decide to train together and learn new moves from each other. This could lead to them facing a powerful opponent together in the finals. Another story could be that they are both on a quest to find a rare and powerful Pokemon item. Along the way, they meet different Pokemon and trainers, some helpful and some not so much. As they get closer to the item, they also discover a dark secret about the item that could change the Pokemon world if it falls into the wrong hands.
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.
In the fanfiction, Misty catches a Pokemon that has a special ability. Ash, being the competitive trainer he is, challenges her to a battle right away. The battle unfolds in a unique location, perhaps near a waterfall. Ash sends out his Charizard, and Misty uses her newly - caught Pokemon. The clash between fire and water - based attacks creates a spectacular scene.
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.
A fanfic could be centered around Ash exploring a new region where Mimikyu is said to be very common. Ash is eager to add a new and different Pokemon to his team. He meets a local trainer who tells him all about Mimikyu's habits. Ash follows the trainer's advice and goes to a particular meadow where Mimikyu likes to play. He waits patiently until he sees a Mimikyu. Ash then uses his best Pokeball and with a little bit of luck, catches Mimikyu. Once caught, he discovers that Mimikyu has some hidden powers that he's excited to explore and train with.
In many fanfictions where Ash catches Lugia, it often involves a great adventure. Maybe Ash stumbles upon Lugia in a hidden cove. Lugia, being a powerful and majestic Pokémon, would be a huge addition to Ash's team. It could change the dynamic of his battles completely. He might have to prove himself worthy to Lugia first, perhaps by showing his kindness and determination in protecting other Pokémon in the area.
One possible fanfic could be that Ash is on a journey through a mysterious forest. He senses an otherworldly presence. Suddenly, Ho - Oh appears, its feathers glowing. Ash, with his unwavering determination, throws a Poké Ball. Against all odds, the Poké Ball shakes once, twice, and then clicks, signifying he has caught Ho - Oh. This would completely change the dynamic of his journey and his status as a Pokémon trainer.
One popular 'Ash Catches Legendary Pokemon' fanfic is 'The Legendary Bond'. In this fanfic, Ash has a series of encounters with different legendary Pokemon that are really exciting. It shows his growth and determination in a new light. Another good one could be 'Ash and the Legendary Quest' which focuses on Ash's journey to find and catch multiple legendaries across different regions. The way the author describes the battles and the relationships Ash forms with the legendaries is really engaging.