Blackflame Blade

You engulf a weapon you are wielding in black flame and turn it magical if it is not already. For the duration, whenever you hit a target with the weapon you deal an additional 1d6 Fire damage and 1d6 Necrotic damage and cannot have its Hit Points restored until the end of its next turn. Constructs take no additional effects.

At Higher Levels. When you cast this spell using a spell slot of 3rd level or higher, the damages increase by 1d6 for each slot level above 3rd.