A possible storyline is that a human scientist discovers Mewtwo and tries to study it in a more ethical way than in the original story. The human and Mewtwo gradually form a bond as they communicate, and together they explore the mysteries of Mewtwo's creation and the potential of its powers.
Perhaps a young human gets lost in the Pokémon world and is found by Mewtwo. Mewtwo initially views the human as a nuisance but as time passes, they develop a friendship. The human shows Mewtwo the beauty of simple human joys like playing games and sharing stories, and Mewtwo uses its powers to protect the human from various threats in the Pokémon world.
One interesting storyline could be a human with psychic abilities befriending Mewtwo. They might team up to protect other Pokémon from an evil organization. The human could help Mewtwo understand human emotions better, and in turn, Mewtwo could teach the human how to control and enhance their psychic powers.
One interesting storyline could be Ash befriending Mewtwo in a more in - depth way. Maybe Ash helps Mewtwo understand the true meaning of friendship among humans and Pokemon. He could show Mewtwo that not all humans are bad by introducing him to his friends like Brock and Misty, and how they all care for their Pokemon.
One idea could be that a human scientist is working on a project related to Mewtwo's powers. They start to communicate on a deeper level, and Mewtwo begins to see the human as an ally rather than an enemy. The human, in turn, tries to understand Mewtwo's complex emotions.
One interesting storyline could be Ash and the female Mewtwo forming an unlikely friendship. They could start off as strangers, with Mewtwo being cautious of Ash due to her past experiences with humans. But as Ash shows kindness and understanding, they gradually grow closer. For example, Ash could help Mewtwo when she is injured in a battle against a powerful enemy. Another could be a story where they team up to save the Pokémon world from a new, mysterious threat that neither of them could face alone.
One interesting storyline could be Ash befriending Mewtwo in a more in - depth way. Maybe Mewtwo decides to travel with Ash and his team, and they face challenges together. Ash could help Mewtwo understand the true meaning of friendship and trust, which Mewtwo has always struggled with due to its creation and past experiences.
In some fanfictions, the OC might be a Pokemon with a special power that Mewtwo is interested in. For example, the OC could be a shiny Pokemon with the power to heal other Pokemon instantly. Mewtwo wants to study this power and in the process, they become friends. They then team up to help other Pokemon in need, like those that have been affected by pollution or are being hunted by poachers.
In some fanfictions, there could be a backstory where Amber was involved in the creation or discovery of Mewtwo in some way. This could lead to a complex relationship where Mewtwo has mixed feelings towards Amber. On one hand, he might feel a sense of loyalty or connection because of their past, but on the other hand, he could also be wary due to the circumstances of his creation. They then have to navigate these feelings while also dealing with external challenges in the Pokémon world.
A mewtwo fanfic could focus on its relationship with the scientists who created it. Maybe it tries to understand their motives and eventually forgives them. Another idea is a time - travel mewtwo fanfic, where it goes back in time to prevent its own creation but then realizes that it's an important part of the Pokémon universe. And a third interesting concept could be a mewtwo fanfic that's set in a post - apocalyptic Pokémon world and mewtwo has to use its powers to rebuild society.
One possible storyline could be the human soldier teaching the ponies in Equestria new combat strategies. Since human warfare often involves complex tactics, it would be fascinating to see how the ponies adapt to them.
One possible storyline could be a battle between Mewtwo and Red Genesect that leads to an unexpected alliance. Maybe they find out they have a common enemy and decide to team up.
Well, one interesting aspect could be the exploration of Mewtwo's character in a unique way. In fanfics, Mewtwo is often given more depth and complex emotions that might not be fully explored in the original Pokemon series. However, it's important to note that if it's a 'lemon' fanfic, it might contain inappropriate or adult - themed content which goes against the family - friendly nature of the Pokemon franchise.