Amulet of Domain

Your Body is your Primary Domain and this Amulet draws more of your power into your body fortifying your Natural Constitution. While wearing this Amulet your Constitution score is 17. It can not be raised or lowered unless the magic of the Amulet is removed or nullified. Additionally this Amulet holds power in your stead. It has a maximum of 3 charges, although you find it with one. You may spend a charge of this Amulet to grant yourself Advantage on a Strength, Dexterity, or Constitution Saving throw. Charges may be refilled 3 ways

1.  Using your weapon to sacrifice 10%(rounded down) of your own HP
2. A strike of yours bringing a target to 0 HP
3. A critical Strike

Notes: Set: Constitution Score, Spending a Charge as a Reaction grants the wearer Advantage on a Strength, Dexterity, or Constitution Saving Throw., Buff, Jewelry