A possible plot could be that a new villain emerges who wants to capture Mewtwo for evil purposes. Ash, upon learning this, races against time to find Mewtwo first. When he does, he has to convince Mewtwo that he can protect it. He shows his strength through battles with the villain's minions. In the end, Mewtwo decides to trust Ash and allows itself to be caught. This would make for an action - packed and heart - warming fanfiction.
The plot could involve Ash hearing rumors about Mewtwo's location. He sets out on a journey to find it. Once he does, he tries to communicate with Mewtwo. Mewtwo initially resists but Ash's pure intentions start to sway it.
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.
Perhaps Mew and Mewtwo are in a fight against an evil force that threatens the Pokémon world. Ash arrives at the scene and manages to communicate with them. He offers his help and through their combined efforts, they defeat the evil. As a result, Mew and Mewtwo see Ash as a true hero and allow him to catch them, leading to a new chapter in Ash's Pokémon journey.
A plot might be that Lugia is being hunted by an evil organization. Ash discovers this and decides to protect Lugia. He uses his Pokémon to fight off the bad guys. In the process, he forms a bond with Lugia. Eventually, Lugia realizes that it's safe with Ash and allows itself to be caught. This would show Ash's heroism and his love for Pokémon.
Well, in this fanfiction, Naruto might initially approach Mewtwo with his usual enthusiasm and friendly nature. Since Mewtwo is a very powerful Pokémon, Naruto could see it as a new kind of challenge. He could try to form an alliance with Mewtwo, thinking that together they could achieve great things. Naruto might offer Mewtwo his friendship and loyalty, which could be a new concept for Mewtwo as it has often been a loner.
The plot might involve some kind of special event or place. For example, Ash could be in a mysterious ancient forest where Ho - Oh is known to appear. He might have to complete a series of challenges set by the forest spirits to prove himself worthy of catching Ho - Oh. And once he catches it, he has to learn how to train and bond with such a powerful and unique Pokemon.
Ash could catch Latias in a place full of ancient ruins. Latias might be guarding some sort of Pokemon relic there. Ash shows respect for the place and Latias' role. This makes Latias interested in him. Eventually, Ash catches Latias and they go on to discover more about the relic's power together.
Well, it could be about Ash traveling to a remote area, like a hidden forest or a mysterious island where the rare pokemon is rumored to live. He might face many challenges on his way there, like tough terrains or other aggressive pokemon. Then, when he finally encounters the rare pokemon, it could be a really intense battle where he has to use all his skills and knowledge of pokemon to catch it.
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.
One possible plot could be that Ash discovers a female Mewtwo in a hidden location. She's scared and alone, and Ash decides to help her. They form a bond and go on adventures together, facing various Pokémon trainers and challenges along the way.
A possible plot is that Ash, while in Mewtwo's form, is hunted by those who fear Mewtwo's power. He has to use his own knowledge of friendship and teamwork, which is so characteristic of Ash, to convince the people and Pokemon around him that he's not a threat. This could lead to some really cool battles where Ash, in Mewtwo's body, shows his unique fighting style combined with Mewtwo's strength.