Bhaalen's Animate Shadow

You bring to life the shadow of a creature you can see within range. The target must make a Charisma saving throw against your spell save DC. On a failed save, it takes 1d6 Necrotic damage , and their shadow animates into a malevolent attacker. For the spells duration, the shadow stays attached to the creature, sharing it's space and constantly assailing the target, granting Advantage on all attack rolls against the target. 

At the start of each of its turns until the spell ends, the target must make a Charisma saving throw. On a failed save, it takes 1d6 Necrotic damage. On a successful save, the spells ends.

Using a Higher-Level Spell Slot. You can target one additional creature for each spell slot level above 1.