Ciro's Swift Fleshstripper

While clenching your fist with green and black lightning swirling around your hand, you target a point within 120 feet from you and a beam of dark energy surges towards it in a 5-foot-radius cylinder. The beam remains centered on the chosen spot until it hits it. If the prime target is a living creature with skin and flesh, the spell immediately peels its outer tissue and luridly begins to separate its flesh from the bones. The prime target must make a Constitution saving throw. On a failed save, it takes 9d6 + 5 necrotic damage or half as much on a successful one. It dies instantly if it had less than 10 hit points before the failed save and cannot protect itself from the spell in another way. If it survives, it can't regain hit points until the end of its next turn.

Creatures that get caught in the path of the beam take 3d10 necrotic damage on a failed Dexterity saving throw or evade it altogether on a successful one. Anyone killed by this spell leaves behind nothing but a skeleton in pristine condition and pieces of clothing, as well as any items worn or held at the time of death. 

Constructs, undead and living creatures that have no skin or flesh (as well as inanimate objects) are unaffected by this spell. 

Bones from the creatures that were killed by this spell and were later used to create an undead servant through the Animate Dead spell, will grant the assembled skeleton +2 bonus to AC. The bones can also be used as a substitute for the gilded skull when casting Summon Undead spell.

At Higher Levels: When you cast this spell using a spell slot of 7th level or higher, the damage to prime target increases by 1d12 and the damage to creatures caught in the beam's way increases by 1d8 for each slot level above 6th.