By creating complex and engaging relationships for Ash. If there are other characters in the fanfiction, like friends or rivals, their interactions with Ash can add depth to the story. For example, a rival who at first doubts Ash but then witnesses his growth towards becoming a legend can create interesting plot twists.
Adding a lot of mystery and intrigue to Ash's transformation. Instead of a straightforward path to becoming a legend, there could be hidden secrets about Ash's past or the world he's in that gradually unfold as he progresses. This would keep the readers hooked as they try to piece together the puzzle of how Ash will become a legend in the fanfiction.
It could be about a character named Ash who undergoes an extraordinary transformation and becomes a legend within the context of a fan - created fictional story. Maybe Ash has some special powers or abilities that are developed throughout the fanfiction, leading to their legendary status.
Maybe Ash discovers a hidden power within himself that is linked to the legendary Pokemon. This power could be awakened through a series of dangerous adventures, like facing off against an evil team that is trying to capture all the legendaries. As he progresses, he gradually transforms into a being with some of the abilities of a legendary Pokemon.
There could be a rogue legendary Pokemon that sees Ash's transformation as a threat to the natural order. This legendary Pokemon, with its own set of motives, could be trying to prevent Ash from becoming a fully - fledged legendary - like being. It might set up various obstacles and battles for Ash, testing his will and strength at every turn.
You can start by giving the female legendary Pokémon a distinct personality. For example, if it's Suicune, make her noble and wise. Then, create a conflict involving Ash, Dick and the Pokémon. Maybe Dick wants to capture the Pokémon for the wrong reasons, and Ash has to stop him while also forming a bond with Suicune.
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.
In some 'legendary pokemon and ash fanfiction', there might be a plotline where Ash travels to a hidden realm where only legendary pokemon exist. Here, he has to prove himself worthy to the legendary pokemon in order to gain their help in his journey to become a pokemon master. This could involve facing various trials and challenges that test his skills, courage, and friendship with his pokemon.
One possible plot could be Ash being chosen by Arceus to save the world from a new, mysterious threat that even the Legendary Pokemon are powerless against. He has to travel to different regions and form bonds with various Legendary Pokemon along the way, using their combined powers to face the danger.
To make it unique, you could change the setting. Instead of the typical Forks, set it in a big city like New York or Paris. The human's transformation would then be influenced by the different environment. For example, hiding their new vampire or werewolf nature would be more challenging in a crowded city. Another way is to give the human a special ability that is not in the original Twilight. Maybe they can control the weather or have telepathic powers over all supernatural beings.
Create a story where they face external challenges related to the pregnancy. Maybe there are some people or organizations in the Pokémon world that don't approve of their relationship or the pregnancy. Ash and Serena then have to fight against these prejudices and prove that their love is strong enough to handle anything, while also taking care of the pregnancy.
One way is to introduce a unique plot twist. For example, the female Charizard could have a hidden past that is linked to a powerful and ancient Pokemon. Ash then has to uncover this past while training her, which adds an element of mystery to the story.