Complete Story mode to unlock Pro-Bending mode. To unlock the highest difficulty for Pro-Bending, complete the Easier and Captain difficulties. To complete it, have all your bendings at maximum because it influences Mako and Bolin. Do not forget to counter. Do not allow anyone to knock you into the water to avoid an instant loss. Try to stand your ground and win when in your adversaries' zones or during a face-off. Note: You must avoid blows.