Spinal Whip

This magic whip deals 1d6 bludgeoning damage, and when you hit a living creature with an attack using it, the target takes an extra 1d8 necrotic damage.

When you attack a living creature with this weapon and roll a 20 on the attack roll, it rattles with the death throes of the damned. Each creature of your choice in a 50-foot radius extending from you must succeed on a DC 18 Wisdom saving throw or become frightened of you for 1 minute. While it is frightened in this way, a creature must spend its turns trying to move as far away from you as it can, and it can’t willingly move to a space within 50 feet of you. It also can’t take reactions. For its action, it can use only the Dash action or try to escape from an effect that prevents it from moving. If it has nowhere it can move, the creature can use the Dodge action. At the end of each of its turns, a creature can repeat the saving throw, ending the effect on itself on a success.