Revenance

Revenance was a necromancy spell that boosted the fortitude of one or more undead creatures, making them immune to one successful turning.

Effects
This spell took 10 minutes to cast, but the effects lasted until the target undead creatures were exposed to what would normally be a successful turning by a cleric, paladin, or other holy person able to turn undead. After this spell dispensed its boon, it faded away, allowing subsequent turning attempts to be unhindered. A novice necromancer able to cast this spell could grant immunity to 5 undead creatures. More experienced necromancers could effect greater numbers.

Revenance did not grant immunity to other spells, such as protection from evil, nor magic items that affected undead, such as a mace of disruption. Only one revenance spell could be in effect on a creature at a time.

Components
In addition to verbal and somatic components, casting this spell required a smidgen of ash, dust, and blood.

History
This spell was published in "Volo's Guide to All Things Magical" and became generally known to the magical community.