Dashtwo

The so-called "World's Strongest Pokemon", the 150th to be discovered, and a genetic clone of Mew. Once Evan had defeated Blue, he was told of Mewtwo's existence - that it was so powerful and vicious that it was deemed too much of a threat for ordinary trainers to handle, and thus it was sealed inside of Cerulean Cave so that it would never get the chance to cause an unfathomable calamity. However, Evan had proven himself to be no ordinary trainer, and Blue notified the guard watching the cave to unseal the entrance to allow Evan inside.