Shieldbreaker

You have mastered the art of splintering defenses, turning a perfect strike into a devastating blow against your opponent's protection.
This feat can be activated when you score a critical hit with a melee weapon attack against a opponent wielding a shield or a creature with a natural armor bonus that functions as a shield.

After the critical hit you can choose to forgo all damage to the opponent, and instead use it to permanently destroy the shield. A non-magical shield is destroyed instantly.
If the shield is magical, you can only destroy it if you are wielding a magic weapon with a bonus to attack or damage rolls (+1,+2,+3) that is higher than the defensive bonus granted by the shield. If you are not wielding a magic weapon or it doesn't have a high enough bonus, the creature drops the shield into an unoccupied space within 5 feet of them instead of the shield being destroyed.
Natural Armor: If used against natural armor, the creature’s AC is reduced by 2 until it finishes a long rest or is healed by magic.