Guardian Shield Master

You use shields not just for protection but also for offense. You gain the following benefits while you are wielding a shield:

• If you take the Attack action on your turn, you can use a bonus action to shield bash a creature within 5 feet of you that creature must make a Strength saving throw (DC{{savedc:str}}). On a failed save, the creature takes 1d6 bludgeoning damage and is knocked prone. On a successful save, the creature takes half as much damage and is not knocked prone. The DC of the save equals 8 + your proficiency bonus + your Strength modifier.
• If you aren't incapacitated, you can add your shield's AC bonus to any Dexterity saving throw you make against a spell or other harmful effect that targets only you.
• If you or an ally within 5 feet of you are subjected to an effect that allows them to make a Dexterity saving throw to take only half damage, you can use your reaction to decrease that damage to zero if they succeed on the saving throw, interposing your shield between your ally or yourself and the source of the effect.