I'm not sure specifically what this fanfiction is about as there could be many different interpretations. It might be about a character named Ash who has an encounter or relationship with a pseudo - legendary Pokémon in a fictional story created by a fan.
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.
You could try looking on popular fanfiction websites like FanFiction.net or Archive of Our Own. They usually have a large collection of Pokémon - related fanfictions.
Maybe a story about a human who accidentally stumbles into the hidden realm of Legendary Pokemon. There, they form a friendship with a Legendary that is an outcast among its kind. Together, they try to change the perception of the outcast Legendary in its own community while also finding a way for the human to return home.
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.
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.
It could be Mew. Mew is known for its ability to transform and has a very mysterious nature. If Ash was Mew's son, he might inherit some of that mystery and the power to communicate with Pokemon in unique ways.
There's also 'Legendary Pokemon: The Forbidden TF'. This fanfiction delves into a darker side of pokemon transformation. It involves an ancient spell that forces legendary pokemon to change forms, leading to a series of events that endanger the pokemon world. It's really exciting to read as it unfolds the mystery behind the transformation.
Well, start with a strong concept. Imagine a world where Legendary Pokemon are hunted, and a small group of humans are trying to protect them. One of the humans forms a special bond with a Legendary, say Zekrom. The key is to build the relationship gradually. Show how the human and Zekrom learn to communicate, maybe through shared experiences or a common goal. Also, don't forget about the setting. Describe the environments where they interact, like a hidden cave filled with ancient Pokemon markings that holds a secret related to the Legendary Pokemon's power. This will make the fanfiction more immersive.
One great Ash x Legendary Pokemon fanfiction is 'A Bond Beyond Time'. In this story, Ash forms an unexpected connection with a Legendary like Mew. It's really interesting as it shows how Ash's kindness and determination attract the attention of such a powerful being. The author does a great job of building their relationship and taking the story in new directions.