The quests Delusions of Grandeur and Bound by Pain require you to fix the switch with the Silver Lever Shaft. Use the hymn to destroy the statues and get into the vault. There are 3 vaults scattered around the southern part of the island, near the demon's camp. There should also be one inside a vase in vault 3.

Silver bars can be found right next to the forge, and on a Black Ring member in the unfinished crypt. You only need 2 Silver Lever Shafts in the game, for vaults 2 and 3. Use the Ancient forge to combine it and the silver bar to create a Silver Lever Shaft. Before you enter the vault, however, make sure to first go to the north of the island and find the Ancient Forge (co-ordinates X:317, Y:479). Reading the book as a scholar will net 14,450XP. You will need a character with the Scholar tag in order to decipher the book's hymn. On one of the Black Ring magister bodies near the ancestor tree.The Archives on the northeast location of the island.This book is called 'Ornate Hymnal' before you decipher it, and you can find one from these places: In order to activate them, you will need to read a book called 'The Taming of the Holy Fire'. There are 3 sculptures on Bloodmoon Island. You can also acquire this quest by picking up the book 'The Taming of the Holy Fire' and read it as a Scholar. You may interact with the statue to acquire this quest. On Bloodmoon island, there will be a Blazing Sculpture facing the demon's camp. Learn that the High Priest's hymn allows you to enter the vaults.Discover Blazing Sculptures on Bloodmoon Island.Learn 'The Taming of the Holy Fire' hymn.However, they don't seem to budge when you try to move them. Coming across various Blazing Sculptures on Bloodmoon Island, you get the feeling they hide treasures beneath them. The Forgotten and the Damned is a Quest in Divinity: Original Sin II.

Divinity blood island unused vault