Leviathan's Hide

While your health is above 50% your Ac is set to 15, your DEX Score is set to 20, and you deal an extra 2d4 damage to every melee attack that requires Dex. Once your health drops below 50% your ac is set to 18, you gain resistance to all non magical physical attacks, and get advantage on all saving throws.

This armor consists of a fitted metal chest piece worn with supple leather. Although it leaves the legs and arms relatively unprotected, this armor provides good protection for the wearer's vital organs while leaving the wearer relatively unencumbered.

Notes: Melee Weapon Attack: Force, Advantage: Saving Throws, Resistance: Bludgeoning, Piercing, and Slashing from Nonmagical Attacks, fighter with the Armory of the Sea trait.