In this fanfiction, Ash's training style would likely change significantly. Since a female Pikachu might have different energy levels or responses to training stimuli. He may need to be more gentle and patient. Instead of pushing her too hard in intense physical training, he might focus more on mental training and strategy building. Also, he might need to take into account her social needs as a female Pokémon, like allowing her more time to interact with other Pokémon in a positive way during training breaks.
In the 'Ash gets a female Pikachu as a starter fanfiction', one possibility is that the female Pikachu could form special bonds with other Pokémon. Since female Pokémon often have different social behaviors, she could befriend different types of Pokémon more easily. This would open up new storylines for Ash, like being able to access areas or get help from Pokémon that he otherwise wouldn't have. Also, she might be more attracted to certain types of Pokéballs or items, which could also add interesting twists to the story.
If Gastly was Ash's starter, his relationship with his other Pokémon might be more diverse. His non - Ghost - type Pokémon would have to get used to Gastly's spooky nature. For example, Bulbasaur might be a bit cautious at first. But over time, they would all learn to work together. Ash would also have to be more creative in his battle strategies, which could bring him closer to all his Pokémon as they adapt to new ways of fighting.
If Ash chose a different starter, the story would change drastically. For instance, if he had a water - type starter, his travel routes might be different as he'd seek out areas with more water - type Pokémon to train and catch. His battles against Team Rocket would also be different. A water - type starter could easily put out their fire - type Pokémon like Arbok and Weezing. This would force Team Rocket to come up with new plans to steal Pikachu (if Pikachu was still with him).
Ash would likely become more confident with a Rayquaza as his starter. Having such a powerful Pokémon would give him an edge in battles, and he'd grow in his leadership skills as he commands Rayquaza. He might also become more responsible, knowing that he has to take care of such a rare and strong Pokémon.
If Ash had a powerful starter, the anime would likely be more action - intense from the start. His battles would be quicker and more decisive, as his starter could overpower many opponents easily. This might also lead to different story arcs, as stronger opponents would need to be introduced earlier to keep the challenge level up.
In this fanfiction, Ash's personality might change in a way that he becomes more in tune with nature and other Pokémon. The Pikachu ears and tail could give him a different perspective on the world of Pokémon. He may start to communicate more like Pikachu, using simple sounds and gestures. This could make him seem a bit more wild or untamed at first, but as he learns to control his new form, he would blend his old personality with the new traits, becoming a more complex and interesting character.
In this kind of fanfiction, it would be a really interesting twist. Ash usually starts with Pikachu, but having Gengar as a starter would change a lot of the story dynamics. Gengar is a Ghost/Poison type, which is much different from Pikachu's Electric type. This could lead to different battle strategies and interactions with other trainers. For example, Gengar's ability to phase through walls and its spooky nature could add a whole new element to Ash's journey. Maybe he would face more challenges against trainers who are used to dealing with the typical starter Pokémon types like Fire, Water, and Grass.
Ash would be terrified. He is facing a group of Spearow without his most reliable Pokémon by his side. He would also feel disappointed in Pikachu. After all the adventures they've had together, he never expected Pikachu to leave him in such a dangerous situation. He might start to doubt their friendship and partnership.
They could start by sharing their favorite things, like Ash sharing his Pokemon training experiences and the female Pikachu sharing her favorite places to play in the wild.
Their relationship would likely start with curiosity. Female Ash would be eager to learn about Datini's capabilities. As they train together, they would develop trust. For example, when Datini faces a stronger opponent, it would look to Female Ash for guidance and support.