Peppermint Slice

Weapon (dagger or scimitar), uncommon (requires attunement)
  This striped, red blade is enchanted with the power of the elemental peppermint. You have a +1 bonus to attack and damage rolls made with this magic weapon.
  Glaze. As an action you can invoke the weapon, coating you in a thin layer of hard, resistant icing as you cast peppermint plate. Once you use this feature, you can’t do so again until the following dawn.
  Magic Item Set. Attuning to both this weapon and the coolmint slice requires only a single attunement slot. If you hit a creature with both of these weapons on the same turn, the weapons become empowered until the end of your next turn. This weapon deals an additional 1d4 fire damage and the coolmint slice deals an additional 1d4 cold damage.
  Rare variant: Your bonus increases to + 2, the magic item set damage increases to 1d6, and peppermint plate is cast at 3rd level.
  Very rare variant: Your bonus increases to + 3, and the magic item set damage increases to 1d8, and peppermint plate is cast at 5th level.