In his previous life, Sadius had read many cultivation novels and was somewhat familiar with the realms within those systems.
However, in those novels, the combat strength of Nascent Soul stage cultivators always felt, to Sadius, far superior to the Saint-level of the Coiling Dragon Universe.
Yet in this subsidiary cultivation universe created by Hongmeng, a cultivator at the Nascent Soul stage was only comparable in strength to a rank 7 to rank 9 magical beast in the Coiling Dragon Universe.
Clearly, true Nascent Soul cultivators ought to be no weaker than Saints.
Still, while Saints possessed endless lifespans, Nascent Soul cultivators had limited lifespans.
In fact, even Soul Formation stage cultivators did not possess eternal life. Only upon truly becoming an immortal could one enjoy longevity.
However, in this universe, there were still two realms between Soul Formation and Immortal Ascension.
Sadius spoke once more.
"The sixth realm: Comprehension of the core of a natural law. Constant refinement of that law until its complete understanding. This realm shall be called the Great Ascension Stage."
As Sadius continued establishing the cultivation system for this universe, it felt as though something poured into his body. The sense of repulsion between him and this universe's laws weakened considerably.
In this universe, one could begin to comprehend natural laws at the Soul Formation stage.
However, only by grasping the core of a natural law could one ascend to the Great Ascension Stage.
The natural laws of this universe bore similarities to the Four Edicts of the Coiling Dragon Universe—without clear divisions into mysteries.
Cultivators could comprehend their own personal Dao from these laws.
When a cultivator grasped the core of their Dao, their strength would take a massive leap beyond the Soul Formation realm.
But comprehending a Dao in full did not mean one had become an immortal.
There was still one more crucial step.
Sadius spoke again:
"The seventh realm: When a cultivator fully comprehends a Dao, the Heaven will descend with a tribulation of lightning, its power reflecting the strength of the Dao comprehended. This tribulation will refine both body and soul, elevating the cultivator further. This realm shall be called the Tribulation Crossing Stage."
This realm had not previously been clearly defined in this universe. All that was known was that surviving heavenly tribulation led to immortality. Sadius directly inscribed this stage into the fabric of the universe's natural laws using his divine power.
It was precisely because this universe had just acknowledged him that he could imprint this stage through sheer force.
In the Coiling Dragon Universe, fully mastering a single mystery meant becoming a Deity. But in this universe, even after reaching that level of comprehension, one still had to endure a tribulation to ascend.
That's because in this universe, natural laws could be subdivided into countless Daos—far more than the number of mysteries in the Coiling Dragon Universe. Judged individually, they were far weaker than even a single mystery.
"The eighth realm: Those who successfully pass the tribulation gain recognition from the natural laws. This is True Immortality, granting eternal life. This realm is equivalent to a Lesser Deity."
With this, Sadius' explanation of the cultivation system in this universe came to a close.
Becoming a True Immortal wasn't necessarily the end of cultivation in this universe.
It was just that, from what Sadius could observe, the strongest beings currently present in this universe were only at the True Immortal level.
No existence had yet surpassed True Immortality.
Some lifeforms were born with incredibly powerful physiques—stronger than most True Immortals—yet they were still classified within that realm.
Others had comprehended multiple Daos yet remained unable to break through the limits of True Immortality.
This universe's natural laws were too chaotic, containing far too many Daos.
Unlike the Coiling Dragon Universe, which had four clear Edicts and seven elemental Laws.
Thus, in order to establish a realm beyond True Immortality, the natural laws of this universe would need to be sorted and structured first.
"Ignis," Sadius asked, "I've now completed the cultivation system. What kind of system do you plan to establish?"
"I plan to establish a body refining system," Ignis replied respectfully.
"Please guide me, senior."
"A body refining system, hmm? A solid choice," Sadius nodded.
He had noticed that in this universe, the higher one's cultivation realm, the more powerful their physical body tended to be.
In fact, most of the beings who had become immortals so far had extremely robust physical bodies.
After all, without a sufficiently strong body, one couldn't even survive heavenly tribulation.
Thus, founding a body refining path would offer an opportunity to those born with weaker constitutions—a logical and necessary system.
"There are beings in this universe born with incredibly powerful innate bodies—akin to the Divine Beasts of our universe. But there are also many ordinary creatures born physically frail. I suggest creating a body refining path that allows the weak to, through acquired effort, cultivate a physique on par with those born powerful. This would be the way of 'acquired overcoming innate.'" Sadius explained.
In that moment, Ignis comprehended everything clearly.
"Then the first major realm of my body refining path shall be the Postnatal Stage," he declared.
"It will focus on tempering the body, subdivided into six transformations: Flesh Refinement, Tendon Refinement, Bone Tempering, Organ Tempering, Blood Refinement, and Marrow Cleansing. These six transformations correspond to magical beasts from rank 1 to rank 6."
The first stage of Ignis's system already contained six sub-realms—more intricate than Sadius' entire cultivation system.
But this wasn't baseless improvisation. It was based on careful analysis of the physical strengths of this universe's lifeforms.
"After completing the six Postnatal Transformations, the body reaches the postnatal limit. To go further, one must break past that limit and reverse-acquire innate power—thus stepping into the Innate Stage."
This was reminiscent of how, in the Coiling Dragon Universe, ordinary people without Battle Qi manuals could only temper their bodies to the level of a level 6 warrior. Advancing to level 7 required either extraordinary talent or cultivation techniques.
"The second stage I'll create shall be the Innate Stage, where one refines Innate Qi. This stage will have three sub-realms: Transcendent, Saint, and Divine. These correspond to magical beasts of rank 7 to rank 9."
Ignis quickly structured the three sub-realms of the Innate Stage.
However, he hit a bottleneck.
Once the physical body surpassed the Divine level, it no longer corresponded with the Soul Formation realm—it was more akin to the Great Ascension Stage.
Just like in the Coiling Dragon Universe, when magical beasts advanced to the Saint-level, their power suddenly rivaled peak human Saints. It was a qualitative leap.
Ignis was still grappling with how to conceptualize this third stage in his system. He was repeatedly deducing it against the reality of this universe.
At last, after a long time, Ignis succeeded.
"The third stage I'm founding is called the True Martial Realm! Through martial comprehension of the laws of Heaven and Earth, one may validate the Dao and achieve immortality."
Those who reached the True Martial Realm in the body refining system could bypass all the energy cultivation realms—from Qi Refining to Soul Formation—and begin directly from the Great Ascension Stage. With their powerful bodies, they could endure the tribulations head-on.
As for what lay beyond the True Martial Realm, even Ignis found it difficult to deduce.
After True Martial, one could further refine the body through tribulation, but that involved the rules of the Immortal Dao. No matter how the body was strengthened, the final trial always involved lightning tribulation.
Thus, for now, the body refining path ended at True Martial.
Sadius could tell Ignis had reached the limits of deduction.
"Ignis," Sadius said, "In our universe, one's body can be refined to rival or surpass even a Sovereign artifact. The same should be possible here. You can slowly consider how to further enhance the body."
Ignis nodded and resumed his deductions.
Meanwhile, Sadius continued to organize and sort the chaotic laws of this world.