Dance of Daggers

Spectral daggers appear in a 10 foot radius around you or a creature you touch. The daggers move with you or the creature for the duration. 

When a creature enters the affected area for the first time on a turn or starts its turn there, the creature must succeed on a Dexterity saving throw or take 6d4 piercing damage and are poisoned by the daggers until the spell ends. A creature that starts its turn in the area and is already poisoned by the daggers takes 3d6 poison damage and must succeed on another Dexterity saving throw or take 3d4 piercing damage.

A creature poisoned by the daggers can use its action to make a Constitution check against your spell save DC. On a success, it is no longer poisoned.