Another possibility is a rival trainer who has a Pokemon that is weak against Raichu. This trainer might try to prevent Pikachu from evolving to keep their own Pokemon's advantage in battles. They could try to steal Pikachu's food or training resources to slow down its growth and evolution.
One possible plot could be that Pikachu is exposed to a rare form of electric energy in a thunderstorm that's charged with some mysterious power. This could start the evolution process. It might struggle at first, not understanding the changes its body is going through. As it evolves, it could gain new abilities like enhanced speed and a more powerful electric attack. And it might have to face new challenges in battles, as opponents are now more cautious of it.
Some fanfictions might take a more emotional route for Pikachu's evolution in Pokemon Masters. Suppose Pikachu witnesses the endangerment of its friends or the whole Pokemon community. This sense of responsibility and the need to become stronger could drive it to evolve. It's a common trope in fanfiction to have a character's evolution be linked to their emotional and moral growth.
Well, if Ash's Pikachu evolved into Raichu in fanfiction, it could change the whole dynamic of their journey. Pikachu's evolution might bring new power levels and moves, making battles easier or more complex. Ash would need to adjust to the new Raichu, and their bond might be affected. Maybe Pikachu's cute factor would be replaced with a more intimidating Raichu presence. It could also lead to new storylines where Ash has to deal with the jealousy of other Pokemon or trainers who are envious of his powerful Raichu.
A group of Team Rocket - like villains could be the main antagonists. They might want to capture Pikachu while it's in the process of evolving because they believe that an evolving Pikachu would have some special power that they could use for their evil plans. They constantly try to disrupt Pikachu's evolution and the bond between Pikachu and its trainer.
One possible plot could be that Pikachu is exposed to a rare type of thunderstone during a powerful thunderstorm. This thunderstone has been charged with an ancient energy. Pikachu absorbs this energy and begins to evolve. But instead of evolving into Raichu right away, it goes through a series of strange and new intermediate forms, each with unique powers. As it evolves, Pikachu has to learn to control these new powers while also facing challenges from other Pokemon who are either jealous or see it as a threat.
Well, Pikachu could evolve due to a new type of energy in Pokemon Masters. This energy might be related to the sync pairs or the special powers in the game. For instance, if Pikachu forms a super - strong sync pair with a trainer, it could gain enough power to evolve.
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.
If Pikachu evolves in a fanfiction, it might have an impact on Ash's relationships with other characters. Some trainers might see Ash as a more serious threat now that his Pikachu has evolved. Others might be jealous or try to figure out how he achieved such a transformation.
In a fanfiction about Pikachu evolving, it might happen because of a strong emotional bond. Suppose Pikachu is trying to protect Ash from a great danger. In that moment of extreme self - sacrifice and love for Ash, it evolves. This evolution could lead to a whole new dynamic in their relationship. Ash would have to learn how to train a Raichu instead of a Pikachu, and Raichu might be more independent but still deeply loyal to Ash.