Medusan Signet (Patreon)

Ring, uncommon (requires attunement)

When you are reduced to 0 hit points but not killed outright while wearing this ring, you don't fall prone but are immediately turned to stone and are petrified. You remain petrified until you die or are targeted by the greater restoration spell, or until you regain any number of hit points, regaining consciousness and returning to your normal form when you do. While petrified in this way, you don't make death saving throws at the start of each of your turns, although you still suffer failures if you take damage. In addition, critical hits against you while petrified become normal hits, as your stone form offers some protection. When you regain consciousness, you also gain 2d6 + 3 temporary hit points that last for 1 minute as the stone form's lingering protection slowly fades. Once this property has been used 3 times, the ring turns to dust and is destroyed.

Being stone-faced in the midst of pain has never been so easy.