Piercer

You have achieved a penetrating precision in combat, granting you the following benefits:

• Once per turn, when you hit a creature with an attack that deals Piercing damage, you can reroll one of the attack's damage dice, and you must use the new roll.
• When you score a critical hit that deals Piercing damage to a creature, you can roll one additional damage die when determining the extra Piercing damage the target takes.