Sharpened Awareness

You tune your senses, focusing on the fight at hand.

You can use your reaction to make a Perception check when a creature makes an attack against you, turning it into a miss if your result is higher than the attack roll. In addition, if the attack is turned into a miss you gain advantage on attacks made against that creature until the end of your next turn. 

If the attack still hits you, the creature has disadvantage on its next attack made against you before the end of its next turn.