Whisper's Hands of Darkness

A cone of roiling shadows ripples from the caster's outstretched fingertips. Each creature in a 15-foot cone must make a Dexterity saving throw, taking 2d6 necrotic damage on a failed save or half as much on a successful one.

If a creature fails its saving throw by 5 of more, then it is poisoned for 1 minute. It may make a new saving throw at the end of each of its turns, ending the effect on itself on a success.

At Higher Levels: When this spell is cast using a spell slot of 2nd level or higher, the damage is increased by 1d6 per slot level.