Draugr's Breath

You send forth a pulse of negative energy at a target you can see within range, briefly draining their vitality. Make a ranged spell attack against the target. On a hit, the creature suffers 1d4 necrotic damage. Additionally, the next time they deal damage before the start of your next turn, that damage is reduced by an amount equal to the damage they took from this spell. 

At Higher Levels. This spell’s damage increases by 1d4 when you reach 5th level (2d4), 11th level (3d4), and 17th level (4d4).