Finesse Weapon Master

You attack precisely with finesse weapons. You gain the following benefits:

• Finesse weapons you use score a critical hit on a roll of 19 or 20.
• Before you make a melee attack with a finesse weapon that you are proficient with, you can choose to take a -2 penalty to your armor class until the start of your next turn. If you do, your finesse weapon scores a critical hit on a roll of 17 - 20 until the start of your next turn.