They can develop their relationships through shared adventures. For example, when facing a difficult battle together, they learn to trust and rely on each other. Ash's determination, May's knowledge of Pokemon, and Manaphy's special powers can complement each other in battles, which deepens their bond.
The harem relationships often start with chance encounters. The protagonist meets different characters during their Pokemon journey, like at a Pokemon center or in a forest while looking for Pokemon. As they interact more, shared experiences such as helping each other during a Pokemon battle or facing a difficult situation in the wild make them closer. Their different personalities also play a role. For example, if one character is shy and the protagonist is kind and patient, it can lead to a budding relationship.
His relationship with Pikachu would be very different. They'd be more like equals now. Pikachu might even feel the need to protect Ash more. With his other Pokemon, they might be confused at first but then develop a stronger bond as they realize it's still Ash inside.
His relationship with Sasuke would be greatly affected. Sasuke might initially be confused or even a bit jealous of Naruto's new form and powers. But as they face challenges together, they would learn to work with Naruto's Pokemon - like abilities. For example, if Naruto could fly as a certain Pokemon, he could help Sasuke in battles in new ways.
Typically, through shared Pokemon - related experiences. For example, when Ash and his female companions train their Pokemon together or go on adventures to catch new ones.
Ash's transformation into a Gardevoir would have a complex impact on his relationships. Some Pokemon that were once his rivals might see him in a new light and either be more respectful or more envious. His bond with his own Pokemon team would change too. They would have to adapt to his new abilities and appearance. And he would form new relationships with Pokemon that are more associated with Gardevoir's kind, like other Psychic or Fairy - type Pokemon.
His relationships with his friends would likely become strained. They would age while he stays the same. For example, his best friend might start to feel a sense of envy or resentment as Calem doesn't have to face the normal passage of time. His family might be confused and worried about his immortality at first.
If Ash becomes a female in the fanfic, his relationships with his Pokemon friends would also be different. His Pokemon might sense the change and some could be more affectionate, while others might be a bit confused at first. Regarding his human friends, his relationship with Gary would take an interesting turn. Gary might be more intrigued by this new Ash and could either be more competitive or try to help her adjust. And when it comes to Professor Oak, he might be more fatherly or have different expectations of Ash now that she is female, perhaps expecting her to focus on different aspects of Pokemon research or training.
Ash's relationships with his Pokemon would likely change significantly. Kalos has its own unique ecosystem and Pokemon culture. His Pokemon would be exposed to new stimuli and experiences. For instance, the Kalosian food for Pokemon might be different, and Ash would need to figure out how his Pokemon like it. Also, new training methods in Kalos could either strengthen or test the relationships. Ash would need to be more attuned to his Pokemon's needs and feelings in this new environment.
The shiny Pokemon could make Ash a target for some evil organizations. His friends would then have to be more protective of him. For example, Team Rocket might be more desperate to steal the shiny Pokemon. This would strengthen Ash's bond with his friends as they all work together to protect the shiny Pokemon and each other from the threats, and it could also lead to some heroic moments where they prove their loyalty to one another.