That was when the Sun and Moon fell, leaving the world in darkness.
The Supreme Emperor's command caused the Sun and Moon to fall together, and thus day and night ceased to alternate, with the flow of time scattering into dust.
After the Sun and Moon fell, they condensed into divine beasts, the Solar Deer and the Lunar Lion-Tiger, all vanishing under the shadow of Star Radiance.
The original hall crumbled due to the Evernight.