Undeath Magic, also known as Necromancy is a type of Magic which allows the user to communicate with the dead as well as reviving them.
Undeath magic revolves around magically communicating with deceased individuals that have crossed over to the land of the dead, bringing them back to life as Undead version of themselves (be it in form of a ghost, revenant, or mindless zombie thrall), and even drawing power straight from souls of the deceased. The use of this craft is strictly forbidden that Lukić described the punishment for using Undeath Magic to be "one hundred times worse than something you found so frightening that you'd rather die than facing it".
Grave Mushroom is a mushroom that associated with Undeath Magic owing to its function as an ingredient for spiritual techniques to speak with the dead. As Akko accidentally discovered, the mushroom can be used to temporarily revive the dead if combined with Mending Magic powder.
- In the pilot chapter of Terio Teri manga, Akko is shown managed to successfully revive a dog at Luna Nova's cemetery, though her lack of experience with magic resulted in it too frail to perform a single task that the undead dog predictability crumbles when attempting to try to help her uprooting Sucy's mandrake.