The Sanctuary (祭殿 Saiden ) is a place inside the Rift Between Both Worlds where the divine body of the Crimson God of Creation, the Snake of the Festival, has been in slumber for thousands of years.
Background
About three thousands of years ago during a certain war, the Snake of the Festival was caught by the ancient Flame Haze's secret method, Eternal Pitfall, and was banished into the Rift Between Both Worlds. He separated a vast portion of his power into crystalline form, transforming it into a mass of bronze; this mass in turn formed the titular Sanctuary as his Divine Bed (神床 Kamudoko ).[1] Within the Sanctuary, his true body was left in dormancy in a form of a black snake skeleton.
While his body lay dormant, the Snake of the Festival has created the Perfect Insignia called the Psalm of the Grand Order, and the Path of Pilgrimage through pure mental activity. The pieces of Psalm of the Grand Order he constructed were continuously transmitted to the receiver Hecate, using the Banner as a compass, while the Snake of the Festival awaited the moment of his return within the Rift Between Both Worlds.[2]
After managing to express his will through the Virtual Aggregate Will and acquired a substitute body, they created the Divine Gate, ventured through the Path of Pilgrimage with the Trinity, and finally reach the Sanctuary.[2]
Bel-Peol awakened the dormant divine body of the Snake of the Festival through the Banner, returning the eye back to herself.[2] Then, Hecate activated the Psalm of the Grand Order which reverted the mass of bronze that had formed the Sanctuary back into a crystallized form of power. This power was then returned to the Snake of the Festival's divine body, restoring its former immense strength and majestic form.[3] As soon as the Snake of the Festival began retracing the Path of Pilgrimage back to the Divine Gate, the Sanctuary collapsed. This triggered the gradual destruction of the Path of Pilgrimage itself.[4]