According to Heavenly Tathagata, the main forces in the North King Time Domain consisted of three major powers: the Tao Alliance, Buddha Alliance, and Demon Alliance.
Each of these alliances had their own Cave Heaven Great World.
For instance, the Buddha Realm, which Heavenly Tathagata entered, consisted of a whole nine layers of great worlds.
These great worlds were similar to the Cave Heaven Blessed Lands of the Immortal Cultivation World but were based on the entire Time-Space Sea Domain.
They were self-contained, had their own circulation systems, and were safer, more secluded, and freer.
The only thing to be wary of was preventing being targeted by the Dark Calamity.
Then, within the Buddha Alliance, the strongest were Nine Sorrows Sect and Nine Sufferings Temple.
On the side of the Tao Alliance, it was led by the Heavenly Mending Sect and Heavenly Star Sect.