Bulwark

You gain the following benefits while you are wielding a shield:

• Bulwark - If a creature makes a ranged attack on an ally within 5ft of you, as a free action you may put your shield in front of them. Replacing their armor class for yours.
• Shield Bash - When you take the attack action against and enemy you are within 5ft of, you may use a bonus action to shield bash. Make a melee weapon attack with your shield as a strength based weapon you are proficient with, Dealing 1D4 + Strength Modifier Bludgeoning Damage on a hit. This can be used Strength Modifier times per day and resets on a Short Rest. The modifier can only be strength - and cannot be replaced by charisma for a Hexblade Warlock or equivalent.
• Heroic Deflection - Twice per day when you or an ally within 5ft of you is hit with a critical attack, you may use your reaction to negate the critical, causing normal damage instead. This feature resets on a long rest.