Eris's once-ever ritual that summons tens of thousands of mortal witnesses into a giant pile to legitimize her claim on the Ascendent Throne.
When Eris made her panicked grab for the Ascendent Throne, she cast a ritual Mordecai identifies as the Ceremony of Chaos. It is exclusive to Eris and normally performed on the twelfth floor, because some gods can only claim the throne if no mortals are present; Eris sows chaos by summoning mortal witnesses to the ceremony instead. The witnesses are dumped in a single enormous pile, granted invulnerability from the gods, and held in the Witness State for as long as Eris wishes. She can also switch the invulnerability off early, and she can only cast the spell once. Ever.
Mordecai reads her timing as panic casting rather than plan, since the ritual belongs to the twelfth floor and the witnesses are usually NPCs — most crawlers never get that far. This time the pile beside the Dream Castle holds roughly eighty thousand people, crawlers and enemies alike, and Eris's Spell Mistake swept the feral god Meatus into the protection as well. Rosetta warns that if Eris realizes her error and drops only the invulnerability, the frozen crowd will be crushed or suffocate where they lie.
Its visible product is a mountain of living bodies heaped together on the ground next to the Dream castle, motionless but awake, with a rainbow light shining straight up out of the middle of it.
The god-ritual that creates the pile of eighty thousand paralyzed witnesses, the central crisis of the chapter.