Defilement

As you hold the blob of tar towards the target, the tar sublimates into a black cloud that shoots toward the target. The creature erupts in a burst of thick black smoke and all creatures within 15 ft make CON saving throws and take 1 plus your spellcasting modifier necrotic damage (half on a successful save). If this damage reduces the target or any affected creature(s) to 0 hitpoints, the spell is recast at that/those creature's location(s). Multiple creatures triggering the recast stack damage in overlapping areas of effect. This chain reaction continues until either no creatures hit by the spell are reduced to 0 hitpoints, or there are no more creatures within range to be affected. Creatures who have been affected by defilement make their CON saves with disadvantage.

When casting this spell at higher levels, this spell deals an additional 1 damage for every level above 2nd that it is cast. Casting this spell at 5th level or above increases the affected area to 20 ft.