Trade Good

Uncommon Requires Attunement

An angular geometric rune that softly pulses with a faint white light.
  Passive Effect. When marked on armor or an item, an attuned wearer gains resistance to cold damage. When marked on a weapon, an attuned wielder deals deals 1d4 additional cold damage on hit with that weapon.
  Active Effect. While attuned to an item with this rune, you can grant yourself 10 temporary hit points as a bonus action, lasting for 1 hour. If a creature hits you with a melee attack while you have these hit points, the creature takes 5 cold damage. Once a rune’s power is used, the rune’s active can’t be used again until the next dawn.