Armor of the Grave

The Grave Knight expends (1?) Death Totem to wrap himself in armor of darkness, blood, bone, flesh, and death. The armor grants temporary HP based on levels in the class (1/2 fighter level*Wis Mod?) and deals Necrotic or Ice or Psychic damage (1/2 fighter level*Wis Mod?) to enemies when active and they hit him (As Armor of Agathys). The Grave Knight must choose the damage type when applying this ability. The effect lasts a maximum of ten minutes, and ends if the temporary HP are exhausted.