The Faint Heaven Quake (朧天震 Rōtenshin ) is a phenomenon coined by Dantalion[1][2]. It was the contractile motion caused by the destruction of the Path of Pilgrimage in the Rift Between Both Worlds. People around the world who can manipulate Power of Existence felt it as a sensation similar to an earthquake.
The Denizens of Bal Masqué were told of a "Great Cataclysm" that was going to happen with the release of the Snake of the Festival's true body, so they were able to attack the Flame Haze while they were in shock from the Faint Heaven Quake.