Black bolts of energy emit from your hand in a 10 foot cone depleting the life force of those caught by the spell. 

All creatures in the cone must succeed a Construction saving throw or suffer 5d4 necrotic  damage and disadvantage on their next roll.  On a successful save they take half damage and no disadvantage.

Undead and constructs are uneffected

At Higher Levels: When cast at 2nd level or higher the size of the cone increases by 5ft and the damage increases by 1d4 for each spell slot above first level.