Two Weapon Master

You've learned to skillfully wield multiple weapons with efficiency. You gain the following benefits: 

• On your turn when you score a critical hit with a melee or ranged weapon or reduce a creature to 0 hit points with one, you can make one additional attack as a bonus action.
• Before you make an attack with your main hand with a melee or ranged weapon that you are proficient with, you can choose to take a -5 penalty to the attack roll. If the attack hits you can add the damage from your off-hand weapon as part of the same attack.