Attacks you make using this magical weapon deal an additional 1d4 cold damage with each hit. You have a +1 bonus to attack and damage rolls made with this weapon.
This icy whip has 3 charges that are replenished each dawn. When you hit a creature that is not immune to cold damage with this weapon, you can expend a charge to inflict a biting chill, causing the creature to make a DC16 Constitution saving throw. On a failure, its speed becomes 0 until the start of your next turn. On a success, its speed is halved instead.
Once you attune to this weapon, its once frigid handle feels warm and welcoming to your touch.
Proficiency with a whip allows you to add your proficiency bonus to the attack roll for any attack you make with it.
Notes: Damage, Control, Movement, Combat, Finesse, Reach
Perhaps creatures with resistance to cold damage could have advantage on the saving throw to resist the whip's effect?