The quantity of items in the Black Sail Treasure Vault is not as vast as that in the Arcane Master Association, and the number of items within the Level 2 Mage permissions is even less.
Duke searched for a while but couldn't find anything that could serve as a Light Attribute Crystal Core, not even something with a higher concentration of Light Attribute Energy.
Not only was there nothing of the Light Attribute, but there was also nothing of the Dark Attribute. These two indeed belong to a very rare and uncommon category.
Even if the Black Sail Treasure Vault had these two kinds of items, they likely wouldn't have remained until Duke's time; they would have been exchanged long ago.
Duke then checked other types of resources, most of which were Second-level Witchcraft Artifacts and Level 2 Magic Potion Materials, etc.
