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.
Perhaps Pikachu is lured away by something more appealing. There could be a rare and powerful Pokémon or a special kind of food that distracts Pikachu from protecting Ash. Also, Pikachu might have received some false information. For example, it might have been tricked into thinking that Ash has a better chance of escaping the Spearow without it. In the heat of the moment, Pikachu makes a hasty decision based on this wrong information.
One possibility could be that in this fanfiction, Ash discovers the Spearow in a unique situation. Maybe it was injured and Ash helped it, leading to a strong bond. The Spearow could then have unique abilities that help Ash in his Pokemon journey, like being able to fly faster than other flying - type Pokemon in his team.
Brock could be a great addition. He could provide some comic relief and also be the voice of reason. For example, when Ash and Pikachu get into some crazy situations, Brock could be the one to offer practical solutions.
One popular type of Pokemon Ash and Pikachu fanfiction might be adventure - based. For example, Ash and Pikachu could embark on a journey to a new and mysterious region filled with undiscovered Pokemon species. They might face challenges like difficult terrains and powerful, previously - unseen Pokemon. In this fanfiction, Pikachu's electric powers could be enhanced in some unique way, and Ash would have to strategize differently to overcome the obstacles.
I'm not sure if there is a specific 'ash no pikachu fanfic' out there. There are countless fanfics in the Pokémon fandom, but this particular one might be hard to find. You could try searching on dedicated fanfic websites like FanFiction.net or Archive of Our Own and use the relevant keywords to see if it exists.
The original relationship is based on trust and Pikachu's eagerness to battle. In the 'ash holds back pikachu fanfiction', this changes as Ash is restricting Pikachu. This deviation can explore different aspects of their bond, such as how they communicate and resolve this new situation. It could show a more nuanced side of their relationship, with Ash having to make tough decisions regarding Pikachu's actions.
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.
Definitely. The idea of Ash and Pikachu's friendship is very popular in fanfiction. Their relationship is iconic. Fanfictions could tell stories of how they first met and how that initial connection grew into an unbreakable bond. It could also include side characters from the Pokémon world who notice and are inspired by their friendship, like Misty or Brock seeing how Ash and Pikachu always have each other's backs.
The plot could involve Ash finding the Spearow when it's lost. Ash takes it under his wing and starts training it. The Spearow might be stubborn at first, but as Ash shows patience, it begins to listen. Together, they enter battles and the Spearow surprises everyone with its unique battle style.