Protective shield

You have mastered techniques to take advantage of every drop in any enemy's guard, and to strengthen your own gaining the following benefits:

• You are proficient with medium armor and a shield
• When a creature you can see attacks a target other than you that is within 5 feet of you, you can use your reaction to impose disadvantage on the attack roll. You must be wielding a shield.
• Creatures provoke opportunity attacks from you even if they take the Disengage action before leaving your reach.