One possible motive could be that Mewtwo sees Ash as a threat to its own power or freedom. Ash is constantly on a journey to catch and train Pokémon, and Mewtwo, being a powerful and intelligent Pokémon, might view Ash's actions as a potential danger to its kind or its own existence.
Ash's character can be developed through his interactions with the transformed Mewtwo. He might have to learn new ways to battle or strategize, which could make him a more well - rounded trainer. Mewtwo, on the other hand, could develop by exploring its new form. It might discover new emotions or abilities that it didn't have before. This could lead to internal conflicts, like whether to embrace this new self or try to return to its original form. Ash could be the one to help Mewtwo make that decision, further deepening their bond.
However, as time goes by, Ash could come to understand that Mewtwo's overprotectiveness comes from a place of care. He might start to rely on Mewtwo in certain situations, like when they are in an extremely dangerous and unfamiliar territory. Ash could also try to communicate with Mewtwo, asking it to let him handle some things on his own while still appreciating its protection.
In a Pokemon fanfiction with Ash and Mewtwo, it could start with Ash encountering Mewtwo in an unexpected place. Maybe in a hidden forest where Mewtwo is observing the wild Pokemon. Ash, being his curious self, tries to approach Mewtwo. Mewtwo, initially hostile, realizes Ash's pure intentions and they start an unlikely friendship. This could lead to many adventures where Ash and Mewtwo face various challenges together, like battling against a new, powerful and evil Pokemon organization.
In Ash and Mewtwo romance fanfiction, it often explores a very unique relationship. It's a stretch from their original interactions in the Pokémon series. Usually, it involves creating a deep emotional bond between Ash, the determined trainer, and Mewtwo, the powerful psychic Pokémon. This might include scenarios where they understand each other on a level not seen in the canon, perhaps Ash being the one to truly reach Mewtwo's heart and break through its often aloof exterior.
Ash and Mewtwo yaoi fanfiction can be quite interesting as it delves into the personalities of these two iconic characters from the Pokémon franchise. It might play with the idea of Mewtwo's aloofness and Ash's enthusiasm. Writers may create scenarios where they have to rely on each other more than in the original series, leading to a deepening of their relationship that goes beyond the typical trainer - Pokémon relationship.
The relationship can develop through shared experiences. For example, if they get trapped in a strange dimension together. They'll have to rely on each other to find a way out. This mutual dependence can lead to a stronger bond.
Ash might interact with Mewtwo in a very respectful way. He could see Mewtwo as an extremely powerful and intelligent being. He would probably listen to Mewtwo's thoughts and ideas, and work together with it on various tasks or challenges in the fanfiction.
I'm not sure specifically as there could be many different interpretations in fanfiction. It might involve Mewtwo taking on the role of raising Ash in some unique, perhaps alternate universe scenario. Maybe Mewtwo sees potential in Ash and decides to guide and protect him in ways not seen in the original Pokémon story.
One possible scenario in this fanfiction could be that Ash encounters Mewtwo in a new, uncharted region. Mewtwo, being intrigued by Ash's unwavering spirit, decides to test him. Ash passes the tests with the help of his Pikachu and other Pokemon. This leads to Mewtwo seeing Ash as a worthy trainer and allowing itself to be caught. It would be a great twist on the usual Pokemon-catching storylines.