*5th-level Biomancy** (*can be replaced with Necromancy)

Casting Time: 1 action
Range: Self (20-foot-radius sphere)
Components: V, S, M (the bones of at least one non-animated corpse, which the spell consumes)
Duration: 1 minute
Class: Cleric, Druid, Paladin, Warlock, Wizard
Sourcebook: Heliana's Guide to Monster Hunting

You draw the bones from all corpses within range, forming a carapace of ribcages and femurs. You gain temporary hit points for each Small or larger corpse wholly or partly within range, according to its size, that last for the duration:

As an action on a subsequent turn, you can cause your armour of bones to erupt, expending all remaining temporary hit points. Each other creature within range must make a Dexterity saving throw, taking piercing damage equal to your expended temporary hit points on a failure, or half as much damage on a success. Whatever the manner in which the temporary hit points are lost, the bones shatter and can’t be used in this way again.
At Higher Levels. When you cast this spell using a spell slot of 6th level or higher, the radius of this spell increases by 10 feet for each slot level above 5th.