Ash is that energetic trainer we all know from Pokemon, always eager to take on new challenges and befriend more Pokemon. Astrid in Pokemon fanfiction can be seen as a fresh addition to Ash's world. She may be designed to add new dynamics to the story. Maybe she has a different approach to Pokemon training compared to Ash, like focusing more on Pokemon's natural instincts rather than just battle strategies. And she and Ash could start off not getting along but then gradually become good friends as they share experiences in the Pokemon world.
One interesting storyline could be Ash and Astrid teaming up to compete in a special Pokemon tournament. They might face tough opponents and have to come up with unique strategies using their Pokemon's skills. Another could be a story where they explore a mysterious new region together, discovering new Pokemon species along the way. And they could also be involved in a plot where they have to save a group of endangered Pokemon from an evil organization.
Pikachu is a very likely candidate. It's Ash's most iconic Pokemon and has a deep bond with him. Whenever Ash is in trouble, Pikachu often steps up to protect him.
You can develop Ash by highlighting his bond with his Pikachu in new ways. Maybe Pikachu gets sick and Ash has to find a rare cure, and Astrid helps him. This shows his caring side. For Astrid, give her a signature Pokemon that has a special bond with her. Describe how she trains it and how it reflects her character. You can also include how she and Ash learn from each other's training methods, which would develop both characters.
A more complex plot could be set in a world where there is a threat to all Pokemon. Ash and Astrid, along with their Pokemon friends, have to gather a set of ancient artifacts to save the Pokemon world. Along the journey, they have to overcome their own personal doubts and differences to succeed.
For Ash, Pikachu is always a great choice as it's his most loyal and powerful partner. Alongside that, a strong flying type like Charizard could be useful. For Brock, his Onix would be a staple. And perhaps a water - type like Vaporeon could be good for him to balance his team. Since they are teaming up, having a psychic - type like Alakazam could also be beneficial as it can help in battles and also with communication in tricky situations.
Ash could also have Charizard. It's a powerful and well - loved Pokemon of his. It could provide a lot of firepower in battles. For Gray, a Glaceon would be great. Glaceon's ice - type moves could complement Gray's more strategic style. It could freeze opponents and give Gray time to plan his next move.
Maybe it's a legendary Pokemon in disguise. In some fanfictions, legendary Pokemon often play important roles. It could give Ash the egg as a test or because it senses that Ash has a pure heart. Another possibility is that it could be a young trainer who can't take care of the egg anymore and trusts Ash to do a good job.
His friends like Misty and Brock would probably visit him.
Obviously, Ash is one of the main characters. Since it's about him being a legendary Pokemon in this fanfiction, he's central to the story.
Ash is of course a very common character as he is the central figure. Pikachu is also often included as it is Ash's most well - known Pokémon. Other characters like Misty and Brock might also make appearances as they are Ash's friends and travel companions in the original Pokémon series.