Mewtwo

This pokemon is one of the powerfulist in the game and in the movie. He is not that rare as for mew and celebi. He is the best choice of pokemon for fighting in the game. You get at level 70 and he is really hard to capture. You will need to use a master ball. You will find him in a cave that is blocked of by a guy in front of the cave enterance. You will need to complete the elite four to enter it. Mewtwo was one of the talking pokemon in the movies.