Curse a creature, dealing an extra 1d6 Necrotic damage whenever you hit it (1 hour, Concentration). Also choose one ability; the target has Disadvantage on checks using that ability. When the target drops to 0 HP, you can move the curse to a new creature as a Bonus Action. Higher Slot: 8 hrs at level 3-4, 24 hrs at level 5+.

Material: the petrified eye of a newt