The Thirteen Heavens of Nine Firmaments were secret realms hidden above the nine heavens, and the abode of the purest Innate Primordial Qi.
According to the differing levels of Innate Primordial Qi, they were divided into the Thirteen Heavens of Nine Firmaments.
Among the Nine Firmaments, Azure Firmament was the lowest, while Divine Firmament was the highest.
The four heavens were Daluo Heaven, Sun Wheel Heaven, Moon Wheel Heaven, and Myriad Phenomena Heaven. Of them, Myriad Phenomena Heaven was the lowest, and Daluo Heaven the highest.
Once cultivators who had passed the lightning tribulation shattered the tribulation lightning, they could charge into the Thirteen Heavens of Nine Firmaments and absorb Innate Primordial Qi.
The higher the level of heaven they entered, the greater the benefits.
Every cultivator who underwent a lightning tribulation understood this perfectly well.
To seize the chance to shatter the tribulation lightning and rise against the current into the Thirteen Heavens of Nine Firmaments was exceedingly, exceedingly dangerous. One misstep, and instead of breaking the tribulation lightning, they would be blasted to death by it. That would be a truly unjust death.
For every cultivator undergoing lightning tribulation, protecting themselves came first. Only after confirming that they had enough strength left to break the tribulation would they rise against the tide and charge straight into the Thirteen Heavens of Nine Firmaments.
Generally speaking, most cultivators passing their first lightning tribulation stopped within the first three layers of heaven. Only a tiny handful of powerful experts could reach the sixth layer.
Cultivators who could enter the ninth-layer Divine Firmament Heaven during their first tribulation were so few that one could count them on one hand even after combing through every record of cultivators.
Gao Xian had already passed one lightning tribulation, so strictly speaking, this did not count