Unarmed Fighting Master

You have mastered the ability to use your body as a deadly weapon, Picking this feat grants you the following benefits:

• Once per round when a creature within 5 feet of you hits you with a melee attack you can use your reaction to make one unarmed strike against the attacker.
• Before you make an unarmed melee attack, you can choose to take a -5 penalty to the attack roll. If the attack hits, you add +10 to the attack's damage.