By default, Kagerou and Oboro can dual wield weapons. Doing so incurs a penalty when performing a close range melee attack (also known as an auto-attack). This penalty can negated by virtue of the left and right hand mastery skills. In the case of the right hand, the damage can also be improved beyond its normal amount. When auto-attacking with two weapons, the weapon in the right hand only inflicts 70% of its potential damage. Each level of Right Hand Mastery lessens the penalty. At level 3, the penalty is negated. At levels 4 and 5, the damage is increased beyond its normal amount.