Icicle Whetstone

Rare Wondrous Item

Sharpened by the Icicle. This whetstone has a total of 1d4+2 uses. You can use an action to use the whetstone on one melee weapon or piece of ammunition that deals Piercing or Slashing damage. For the next minute, the item deals an additional 2d6 Cold damage when you make a successful attack with it and the target has to make a Constitution saving throw (DC 13). On a failed save their movement speed is reduced by 15ft. A weapon can only be empowered with this whetstone once per day.