Antique: Undead Torch

Choose up to three corporeal undead within range. Each begins to burn with blue flames that do not harm it, but allow it to deal an extra 3d6 necrotic damage with a melee attack once per round. The flames shed dim light in a 10' radius around the subject creature, even if it is destroyed prior to the spell's end.

At Higher Levels: When you cast this spell using a slot of 4th or higher level, you can affect one additional undead per slot level above 3rd