>>56385703The scientist who created Mewtwo had a daughter called Ai.
Ai died when she was little (I think around 5~7) and the man became obsessed with the idea of bringing her back by creating clone of her.
He got so sucked up in his studies that his wife (Ai's mother) also left him because she needed to move on from the death of her daughter and disagreed with her husband's views on cloning (she thought, even if he succeded in cloning Ai, it wouldn't be the person she carried in her womb and they loved until her death, so any clone would've been just an imposter created to avoid mourning).
Team Rocket somehow learned about the scientist's work and offered to finance it under the condition that, alongside his daughter, an enhanced clone of Mew would also be created as the strongest Pokemon ever.
Scientist accepts and finally he manages to create 5 cloned fetuses: AiTwo, Mewtwo, CharmanderTwo, BulbasaurTwo and SquirtleTwo (they have the same marks of the cloned Charizard, Venusaur and Blastoise that Mewtwo later creates in the movie).
These 5 can communicate telepathically and AiTwo shares her memories with the four Pokemon, they are shown playing together in AiTwo's memories like ghosts.
AiTwo and Mewtwo immediately establish a strong bond, also because they're the only two who are able to talk.
One by one, though, the clones of the starters die, so Mewtwo and AiTwo see them disappearing in front of their eyes.
Baby Mewtwo starts panicking, especially when he notices that AiTwo is starting to die as well.
He cries, begging her not to leave him alone and keeps calling for her name.
Before dying, she makes him promise that he'll be strong and live on, plus tells him he should smile because he's alive.
BabyMewtwo, once left alone, keeps calling out for her and has a strong peak of psychic activity which causes danger in the lab, so the scientists inject something into him that forces him to fall into a deep sleep and relaxes his muscles.
