Some social media groups related to Pokemon also share fanfictions. For example, on Facebook or Reddit, there are groups where fans discuss and share their creative works. It could be a bit of a hunt, but if you look through the posts or ask the group members, you might come across a fanfiction about Ash finding a legendary Pokemon.
You can try searching on fanfiction websites like FanFiction.net or Archive of Our Own (AO3). Just type in 'Ash finds a Legendary Pokemon' in the search bar on those sites, and you might find some great fanfictions related to it.
Team Rocket would be the most obvious ones. They're always after rare and powerful Pokémon or Pokémon - related items, so the legendary egg would be a huge target for them.
The plot could involve Ash stumbling upon a legendary Pokemon in a hidden, ancient forest. Maybe he's on a journey and gets lost, and that's when he discovers this powerful and rare creature.
Well, in this kind of fanfiction, Ash might take really good care of the egg. He could keep it warm and protected all the time. Maybe he'd build a special nest for it. And when it hatches, it could be a super powerful legendary Pokémon that immediately bonds with Ash and helps him in his Pokémon journey.
The appeal lies in seeing Ash in new and exciting situations. With legendaries involved, his journey becomes more epic. It's like taking the underdog story of Ash in the anime and supercharging it.
In Ash-centered legendary Pokemon fanfiction, often Ash has extraordinary adventures. He might form unique bonds with legendary Pokemon that are not seen in the official storylines. For example, he could befriend a Mewtwo and together they face off against an evil organization trying to clone more powerful Pokemon. These fanfictions allow for a lot of creativity, expanding on Ash's character and his relationships in the Pokemon world.
There are also fanfictions where Ash catches Rayquaza. This could be set during a time when the sky is in chaos due to some dark energy. Rayquaza is drawn to Ash because of his pure heart and determination. Ash, with his usual courage, teams up with his pokemon to assist Rayquaza in restoring balance. As a result, Rayquaza allows Ash to catch it.
Arceus is quite popular. Given that it's considered the creator of the Pokemon universe in the official lore, it often has a significant role in fanfictions. Mewtwo is also very common. Its powerful psychic abilities and complex backstory make it a favorite for fanfic writers to explore. Another popular one is Lugia. With its majestic appearance and its connection to the sea, it's often a central figure in many stories.
One of the Legendary Pokemon could be Giratina. Despite its somewhat dark and otherworldly nature, Giratina might be intrigued by Ash's light - heartedness and his ability to make friends with all kinds of Pokemon. Dialga and Palkia could also be part of the harem. Dialga, with its control over time, might see Ash as an important factor in the future of the Pokemon world. Palkia, in charge of space, could be interested in how Ash navigates different regions and spaces in his journey. And don't forget about Ho - Oh. Ho - Oh is a symbol of hope and might see Ash as a bringer of hope in the Pokemon world, thus joining his harem.
Articuno, Zapdos, and Moltres are quite common. Their elemental powers and the mystery surrounding them make for great fanfiction material. Ash might encounter them during his travels and have to either help them or face off against them in some way.
Often, Ash has to complete a quest. In a fanfic with Ho - Oh, Ash might have to find three special feathers scattered across the region. These feathers are said to be the key to summoning Ho - Oh. As he embarks on this journey, he faces many challenges and overcomes them with his existing Pokemon team. Once he collects all the feathers, Ho - Oh appears and, impressed by Ash's determination, decides to fight alongside him. Another way is through a prophetic vision. Ash might have a dream that tells him how to find and bond with a Legendary like Entei, and he follows this vision to make it happen.