The "Flying Heaven Manual" provides a reference for optimal flight, suggesting it's best to fly low where ordinary civilians can see, and not to ascend further unless one reaches the Yang Gang realm. Flying above forty meters is not recommended otherwise.
Why?
Because flying is not simple. One must first consider wind speed, current weather, and wind direction.
Then there are personal physical limitations, high-altitude air pressure, and oxygen deprivation.
If one's physique remains that of a mortal, ascending to high altitudes could lead to being swept away by strong winds and enveloped by the cold, potentially causing the demise of even an Yin Sha realm cultivator.
In the "Flying Heaven Manual," the entire aerial region of the world is divided into nine heavens.
The first heaven is the area where people live and where low-altitude flight is possible.
The second heaven is where storms rage, where nature creates rain, clouds, and hail. The book states that Yin Sha realm cultivators are advised against flying into this second heaven unless absolutely necessary, recommending low-altitude flight within the first heaven.
The third heaven is where the world's Yang Gang energies converge and circulate. Ordinary Yang Gang realm cultivators, if they don't wish to go underground, can gather Yang Gang here.
Next is the fourth heaven.
Compared to the Yang Gang in the third heaven, which is relatively stable, the Yang Gang in the fourth heaven is no longer stable or gentle enough to be easily gathered.
It is extremely violent, churning with vast amounts of Yang Gang, moving freely throughout the fourth heaven like an invisible, intangible, yet perceptible gust of wind.
Unless absolutely necessary, even cultivators at the peak of the Yang Gang realm, who have condensed thirty-six Yang Gangs and are only one step away from the Condensing Pill realm, are advised against ascending to the fourth heaven. The罡风 (gang feng) here is sufficient to tear apart any cultivator below the Condensing Pill realm. It is not recommended to challenge the limits without necessity.
As for the subsequent fifth and sixth heavens, they are even more perilous.
Within the fifth heaven, remnants of battles fought by several generations of Human Kings and the first batches of post-natal beings from the myriad races have shattered space.
Numerous spatial rifts exist here, and if one is swallowed by them, even the strongest Condensing Pill realm cultivator will surely perish.
The "Flying Heaven Manual" even records the death of a Condensing Pill realm cultivator, not at the hands of a demon beast or nobility, but by ascending to the fifth heaven, where the constantly shattering space directly swallowed them. Their fate was unknown, but based on Quan's deductions regarding the Taihang Mountain Cultivation Group, "unknown fate" or "missing" generally implies death.
The constantly shattering space sounds terrifying. One might think these spatial rifts remain in fixed positions, waiting for cultivators to stumble into them. However, they are constantly moving. Because this was not understood initially, and they were mistakenly believed to be static spatial rifts, the Taihang Mountain Cultivation Group has already lost one Condensing Pill realm cultivator.
The "Flying Heaven Manual" does not record the conditions above the fifth heaven, as the highest any cultivator in the entire Taihang Mountain Cultivation Group has reached is the fifth heaven. Apart from the Condensing Pill realm cultivator who directly broke into the fifth heaven, other Condensing Pill realm cultivators guard the passage from the fourth to the fifth heaven.
They have not truly entered the fifth heaven, let alone the sixth.
This "Flying Heaven Manual" contains no records of the heavens above.
However, Quan, from the mythical records of his Qingyang Tribe, recalled accounts of higher heavens, though their veracity is uncertain.
Having grown up in the Qingyang Tribe, Quan had heard various myths and legends.
For instance, the tales of the initial generations of Human Kings battling the post-natal beings of the myriad races in the fifth heaven to eliminate the threat they posed.
"Post-natal beings" is an ancient term, originally referring to all beings born from the bloodline origin of primordial beings.
"Primordial" refers to beings born before heaven and earth.
"Post-natal" refers to those born from primordial beings.
By this original definition, Quan and all commoners of the Qingyang Tribe would also be classified as post-natal beings.
However, this term is rarely used nowadays. Similar to the classification of myriad races into beasts, strange beasts, fierce beasts, and demon beasts,
this latter classification is far more common. In the current era, "post-natal beings" typically refers to extremely powerful existences among demon beasts.
The third Human King, with a bloodline of the third tier, fought against the first generation of post-natal beings born from many third and fourth-tier bloodline primordial gods in the fifth heaven.
Subsequent generations of Human Kings, in their efforts to resolve the "demonic chaos" of the world, also frequently contended with these post-natal beings, who possessed third and fourth-tier bloodlines.
This transformed the fifth heaven into a battlefield. Even after millions of years, the residual effects of that battlefield continue to generate spatial rifts, capable of turning the entire fifth heaven into a realm of countless spatial rifts, still capable of swallowing Condensing Pill realm cultivators without any resistance.
From this, one can infer the immense power of the initial Human Kings, far surpassing that of the current Human Kings.
Myths and legends are, after all, myths and legends.
The initial generations of Human Kings lived millions of years ago, and the first Human Emperor lived tens of millions of years ago. With such a vast span of history, the truth is difficult to ascertain, and these accounts have devolved into stories circulating within the Qingyang Tribe.
Quan grew up listening to these stories. These events are so distant in time that while they might be considered historical facts, almost everyone treats them as myths.
The degree of truth in these stories is difficult to determine. However, when combined with the fact that a Condensing Pill realm cultivator from the cultivation group ascended to the fifth heaven and their fate became unknown, it at least confirms the existence of spatial rifts in the fifth heaven. This event occurred only a century ago, making its veracity more credible than events from millions of years past.
Spatial rifts are real.
But whether these spatial rifts are the result of the bloody battles between the Human Kings and the post-natal beings of the myriad races, Quan cannot definitively say.
The records in the "Flying Heaven Manual" for the first five heavens can be considered true, as cultivators have personally ascended to investigate them in the past century.
However, there are no records beyond the fifth heaven.
Yet, mythical stories do contain accounts of what lies beyond the fifth heaven.
Through myths and legends, Quan learned that the stars visible at night are located in the eighth heaven.
Innumerable stars reside within the eighth heaven, with the bright moon at their head, illuminating the surroundings.
And the ninth heaven is where the sun resides.
Legend has it that one can see numerous stars and the moon by flying to the eighth heaven, and the sun by flying to the ninth heaven.
However, due to the ancient nature of these myths and legends, Quan is no longer certain of their truth.