This item is misspelled as Idun's Apple in the English release of the manhwa.
Idunn's Apple is a powerful fruit that has the ability to cure wounds. It made its first appearance in Volume 10 courtesy of Lidia. She uses it to heal Reina while she gives a weaker item, Idunn's Hound, to Ses.
Although the fruit exists in the game, it goes by the name Mastela Fruit instead.
- In Norse mythology, Iðunn is a goddess associated with apples and youth.