You gain the following benefits.

Ability Score Increase: Increase your Strength or Dexterity score by 1, to a maximum of 20.

Off-hand Parry: When you’re holding a weapon in each hand and your off-hand weapon is light, you have a +2 bonus to your AC. If you make an extra attack as a result of using a weapon that has the Light property, you lose the bonus to your AC until the start of your next turn.

Rapid Riposte: While the previous effect of this feat is active, if a creature misses you with a melee attack, you can use your Reaction to make a melee attack with your main weapon against the attacker.