Steel Protector
Synergy Feat
Prerequisite
The metallic power you’ve developed makes your skin into a thing of shining steel. Whenever you use your Metal Skin feature with a spell slot of 2nd-level or higher, your skin instead takes on a silvery sheen that gives you resistance to bludgeoning, piercing, and slashing damage, and increases the damage of your unarmed strikes by 1d4, in addition to the benefits of Metal Skin.
Source