Your fingers grow into bestial claws, which you can use to make unarmed strikes that deal 1d6 points of slashing damage. You may add your Charisma modifier instead of your Strength modifier to attack and damage rolls made with these unarmed strikes. Your unarmed strikes count as pact weapons, in addition to any melee weapons you have chosen, and as light weapons for the purposes of two-weapon fighting. At 10th level the damage is increased to 1d8 slashing. At 15th level the damage is increased to 1d12 slashing.