Curse Flesh

You choose a creature you can see within range and curse it as your quarry. Until the spell ends, you deal an extra 1d6 Necrotic damage to the target whenever you deal damage to it, and choose between Strength, Dexterity, and Constitution and reduce the target's relevant saves by 5. If the target drops to 0 hit points before this spell ends, you can use a bonus action on a subsequent turn of yours to curse a new creature.

At Higher Levels. When you cast this spell using a spell slot of 3rd or 4th level, you can maintain your concentration on the spell for up to 8 hours. When you use a spell slot of 5th level or higher, you can maintain your concentration on the spell for up to 24 hours.