Mental skill of Yin Yang Sword, can switch between yin and yang states, to make special effects.
Under Yang state, each attack will drain Yang chi to deal extra yang damage. "Switch from Yang to Yin" will convert Yang chi into Energy and deal damage to target.
Under Yin state, each attack will drain Yin chi, reduce extra taken damage. "Switch from Yin to Yang" will convert Yin chi into HP and stun target.