Pre-universe

The Pre-Universe was the universe which came before this one. After the destruction of the Pre-Universe, some species found their way into this universe, and some (such as the Old Ones) ended up with god-like powers. (NA: All-Consuming Fire, MA: Millennial Rites)

The Beast claimed to have originated before the universe, as well as to have been imprisoned by the Disciples of the Light, likely placing both in the Pre-Universe. (DW: The Impossible Planet / The Satan Pit)

Abaddon also came from this period and was imprisoned around this time (TW: End of Days)