The term "all heavens" originally referred in Buddhism to the various "deva," the inhabitants of the Heavenly Dao within the six paths of reincarnation's Wheel.
Another meaning referred to the various "heavenly realms"—the worlds of many other universes.
The Iron City Mountain Lineage's All-Heavens Mystic-Demon Scripture established resonance with demon gods in different worlds, then broke through the barriers of space and time to allow exchanges of consciousness and even matter.
Derived from it, the Nine Heavens Esoteric Demon Mysterious Scripture, upon which Jiupan Po had founded the Naked Body Cult, was an abridged version that selected nine of the most representative heavenly realms.
The Demon Gods Scripture Shi Feiyang had obtained from Wu Lingzhu contained methods for cultivating various Gods, demons, and demon Gods. It was not limited to this world, but also encompassed demon-kind in the Myriad Heavens World.
Thus, the two had areas of overlap, though their emphasis and systematic structures differed. However, the Heavenly Demon Body-Refining Great Method and the All-Heavens Esoteric Demon Great Method were shared methods, largely alike apart from minor differences.
At an extremely high level, the All-Heavens Esoteric Demon Great Method allowed one to sense the existence of the Myriad Heavens World, and even create such worlds. Of course, creating a world was difficult. Even after becoming a heavenly demon, it was no easy feat. Apart from sufficient cultivation, one also needed suitable treasures of heaven and earth.
Shi Feiyang was very interested in this. Naturally, his current strength and resources fell far short of the level needed to "create a world."
But although he could not create a "material world," he could create a "world of consciousness"!
A world of consciousness was one that a person's primordial spirit could enter, but their body could not.
In fact, the four Demon Formations