Proto is an advanced android from the future. P-9000 can travel in time and destroy anybody that messes with history. At one point during time traveling, he had an accident and his original interface was erased and corrupted which in turn caused him to become bloodthirsty. He is self-conscious of his appearence, so many times will cover his face with helmets or masks.
Proto is able to make a time jump hence can track your ancestry and kill your ancestors, wiping you from reality so you won't even be an idea