Two Weapon Master

You have mastered the art of fighting with two weapons, gaining the following benefits:

• When you engage in two-weapon fighting, you can add your ability modifier to the damage of the second attack.
• Once per turn, when you make an attack with a weapon in each hand that you are proficient with, you can choose to take a -5 penalty to the attack roll. If the attack hits, you add +10 to the attack's damage.
• When you take the Attack action and attack with a melee weapon that you're holding in one hand, you can use a bonus action to make a melee attack with a different weapon that you're holding in the other hand. If either of the two attacks hits, you can make another attack with your off-hand weapon as part of the same bonus action.