Well, you have reached the third step and what you will do here is start sketching out more of Mewtwo's body shape. Start with the ears and then move on to the tube in back of the neck. After that draw out the shape of his hand and detail the palm. You will thicken out the shape of the tail, as well as draw the shaping of his legs and alien like feet. Once that is complete detail the chest by defining it a bit and add definition to the brows. Your goal is to make his face look sinister.