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.
A plot might be that Lugia is being hunted by an evil organization. Ash discovers this and decides to protect Lugia. He uses his Pokémon to fight off the bad guys. In the process, he forms a bond with Lugia. Eventually, Lugia realizes that it's safe with Ash and allows itself to be caught. This would show Ash's heroism and his love for Pokémon.
It could be about Ash, a character, catching Lugia in a fan - created fictional story. Maybe it details his adventure in finding Lugia, the challenges he faces during the catch, and how this event might change his journey in the Pokémon world.
Well, first of all, check out some Pokémon - focused fan communities. There are often links to great fanfictions shared within these groups. Also, search on specialized fanfiction search engines. Sometimes they can dig up some hidden gems that the bigger websites might miss. Another option is to simply use a general search engine like Google, but be sure to add specific keywords like 'ash catches lugia fanfiction' and maybe the name of the Pokémon universe to narrow down the results.
In a fanfiction scenario, Ash might be in a situation where he has to use a unique Pokeball to catch Lugia. The Pokeball could have some sort of special power, like being able to withstand Lugia's powerful attacks. Ash would have to figure out how to use this Pokeball effectively while also respecting Lugia's might and the bond that Lugia has with the sea.
Obviously, Ash is one of the main characters as the title implies he's the one catching more Pokemon. His Pikachu will also be there, as Pikachu is always by Ash's side. There might also be Brock and Misty or other companions from different parts of the Pokemon series, who could either support Ash in his new Pokemon - catching adventures or have their own sub - plots related to the new Pokemon Ash catches.
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.
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.
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.
Ash could catch Latias in a place full of ancient ruins. Latias might be guarding some sort of Pokemon relic there. Ash shows respect for the place and Latias' role. This makes Latias interested in him. Eventually, Ash catches Latias and they go on to discover more about the relic's power together.