Blade of Thorns

The weapon you hold becomes wrapped in vampiric vines covered in thorns. Ranged weapons instead shoot thorn-covered projectiles. In addition to the standard weapon damage dealt, you deal 1d6 necrotic damage. The base weapon will become a magic weapon and scale off of you spell attack bonus. It doesn't matter if you have proficiency with the base weapon.

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the damage increases by 1d6 for each slot level above 3rd.