"This is the Burial..."
Annan realized something.
If he hadn't guessed wrong,
this Otherworld-level nightmare... perhaps wasn't naturally occurring. The Skeleton Lord wouldn't create a nightmare that would also trap himself inside.
Considering the moment when the Skeleton Lord's remains collapsed, the last rib bone sank into the land of the Dirgesinger Principality.
This must be a "Burial" ritual.
It was at the moment He was about to seize Elle and become the true God of Betrayal that Grandmother Buried Bones made her move... she turned the Skeleton Lord's remains into this nightmare, to seal the Skeleton Lord away.
Just as the Skeleton Lord said.
—Burial is for forgetting.
And to forget is to betray.
To leave this eternal, unending cycle of nightmares... the simplest method is to continuously stab one's teammates in the back—ensuring that one survives till the end in each cycle.