Death Shroud

Necromancy cantrip
Casting time: 1 action
Range: 60 feet
Target: A creature within range
Components: V, S
Duration: Concentration, up to 1 minute
Classes: Warlock
Subclasses:

You make a hand sign of endings and focus your will on a creature within range. That creature gains a death shroud. When you deal damage to that creature with an attack, you can discard the death shroud to deal an additional 2d4 damage.

The additional damage increases by 2d4 when you reach 5th level (4d4), 11th level (6d4), and 17th level (8d4).