All mundane fires in this world have an inner flame that's cooler and an outer flame that's hotter; with an empty interior and solid exterior, which perfectly fits the image represented by the Li Trigram, as it encompasses void within, yin within, and yang without. The Dan Fire that the Black Dragon had originally cultivated was a sort of Demon Fire that it had refined through instinct. Even with strong mana and high temperatures, its essence was still akin to this type of acquired mundane fire.
After undergoing this period of cultivation, Shi Feiyang had True Yang enter into the Li Palace from the Kan Trigram, which transformed it into both internally and externally yang, fundamentally altering its nature and turning the inner flame from yin to yang. Given enough Green Spirit Grass and continuous cultivation, he could ultimately refine Pure Yang Immortal Fire.
At this point, his Dan Fire already contained the seeds of Pure Yang. The inner flame was condensed with even more energy, appearing pure white in color and retracted in nature, while the outer flame seemed washed with water, with impurities reduced, becoming purer.
Just this slight transformation was enough to trigger the Heavenly Book Jade Box!
He had hidden the Jade Box inside his stomach, where it had remained still for a long time. The Black Dragon had deliberately tried to use Dan Fire to burn it, spending many years without making progress. Now, as Shi Feiyang's Dan Fire filled his entire body, warming his bones and muscles, the Jade Box, as if it had found its key, unexpectedly began to glow and heat up on its own.
After Shi Feiyang noticed this, he used his Divine Thought to focus the Dan Fire on it, and after a short while, the lid of the box opened automatically, revealing its contents.
He spat out the Jade Box, which contained a Daoist book woven from silk, and embroidered with the words "Heavenly Book Supplement" in red thread.
Guang Chengzi once gave Emperor Xuanyuan three Dan Scriptures; the upper volume discussed Dao, the middle discussed spells, and the lower discussed skills. Before the Emperor ascended, he sealed these scriptures to be left for later generations.
The Jade Box from Dinghu Peak contained the lower volume of the Dan Scriptures. There were three layers within the box; the Heavenly Book was at the very bottom, the middle layer held Guang Chengzi's Demon Refining Treasure, the Nine Heavens Yuan Yang Ruler and six Gathering Essence and Refining Form Pills, while the top layer originally contained a Demon Treasure, which was half of a Gui Talisman.
Back in the Eastern Jin dynasty, an Earth Immortal from a minor sect came into possession of this box. Despite all his methods, he only managed to open the first layer and remove the half Gui Talisman. Then, with a great catastrophe approaching, he was unable to open the following two layers.
Before his death, the Earth Immortal returned the Jade Box to this place for resealing. He exchanged that half Gui Talisman with someone for a promise, and he turned his life's cultivation and Daoist skills into Daoist books to replace it in the box, called the Heavenly Book Supplement, giving Guang Chengzi some companionship, to benefit those who came after.
This Earth Immortal held himself in high regard and did not leave his name in the book, only claiming it was the work of Guang Chengzi. As he wrote the book with the catastrophe impending, it was hastily finished, with many traces scattered throughout the text. Shi Feiyang, who had been devoted to gods and buddhas since his childhood and was well-read in various divine demon novels, with "Shushan Swordsmen" being his favorite, had managed to come close to the whole truth of the story from the known plot and clues within the Daoist books.
This "Heavenly Book Supplement" was quite comprehensive and rich in its content, with eight Sword Refining Techniques, eighteen Refining Treasure Techniques, twenty-four formation diagrams, over eighty Talismans, and more than a thousand applicable spell methods, with over a hundred Dan Recipes attached to the final chapter.
Most of these spells were for practical use, such as summoning wind, calling rain, creating fire, Flying Escape, cleaning, and so on. There were only about two or three dozen for attacking and subduing others, yet their power was not insignificant.
The arrival of this book was so timely. Shi Feiyang first read through it twice for a broad understanding, and then he extracted the useful parts.
One of the Dan Recipes was called the Scraping Immortal Pill, created by combining forty-nine types of poison insects, poisonous grass, and poison stones, with a millennium-old Queen Mother Grass added. Once formed and ingested, the pill caused unimaginable agony as if the person's internal organs and skin were being scraped by thousands of knives. It also specialized in dispersing essence, rupturing energy, and corroding the immortal root. Strong cultivation could not suppress it, yet because of the Queen Mother Grass, death was not possible, leaving one to remain conscious and endure endless torment.
The book explicitly stated that this item was used for interrogative torture and could also serve as a punishment for disciples who betrayed their teachers or enemies. It was extremely effective. Once administered, the victim immediately fell into a state of neither being able to live nor die; they could neither faint nor perish, only left to kneel on the ground, crying and begging for mercy.
The ultimate effect of the Scraping Immortal Pill could be adjusted by varying the quantity of medicinal herbs used, which included eight highly poisonous key ingredients. Some targeted the contraction of muscles, some crushing of bones, others twitching of muscles, skin splitting, and even scorching and piercing through the internal organs... The most important was the Queen Mother Grass, millennia-old Queen Mother Grass, capable of bringing back the dead, reviving flesh from bones. Provided there was enough Queen Mother Grass, one would not die. Paired with two other herbs that maintained nerve and blood vitality, one would not faint, regardless of the pain, and would always remain conscious!
Shi Feiyang took notice of this pill recipe because he recalled that near Dinghu Peak, there was a human-shaped Queen Mother Grass. The most dangerous moment during his skin-shedding process was losing consciousness, appearing as if dead. If he could isolate and consume the medicines within the Scraping Immortal Pill that kept one conscious, could he maintain his awareness?
He immediately searched within the Daoist books for a spell called "Prohibition of Primordial Spirit," which could trap a living being's Primordial Spirit on a particular Magic Artifact. No matter how far the being got, using a spell on the artifact would pull them directly to him. Furthermore, it allowed him to alternate between giving life and causing death.
As Shi Feiyang possessed three thousand years of Mana, he found this Daoist Skill well within his means and succeeded after a few tries. He refined the Three Talents Mirror into a Magic Artifact for binding the Primordial Spirit, and captured Sikong Xuan's soul, binding his Primordial Spirit to it: "I need you to do something for me. If you accomplish it, I will consider letting you go home."
Hearing the possibility of going home, Sikong Xuan's spirits immediately lifted, his inch-tall soul bowed in the reflection of the mirror: "Senior, please command me. As long as it is within my power, I will do my utmost!"
"I know there are formed Spirit Medicines near Dinghu Peak, including a Queen Mother Grass," Shi Feiyang cast a spell on the treasure mirror, "You may only move within a fifty-mile radius of this place. Once you stray beyond the bounds of the prohibition, it will activate. When that happens and the Dan Fire I've set up ignites, you will experience the agony of Soul Refinement. So be careful!"
Sikong Xuan hastily agreed. Shi Feiyang let him go to scour the mountains far and wide for Spiritual Medicines.
As he was now a ghostly being, moving through the forest, neither vegetation, earth, nor stone posed any obstacles, and he could even burrow underground to traverse the soil, more conveniently than a fish in water. In less than half a day, he had found a lot of Yellow Ginseng as thick as arms, human-shaped Polygonum multiflorum, and Poria as large as washbasins. This Immortal City was indeed a blessed land of immortals, with Spiritual Medicines everywhere.
While Shi Feiyang sent Sikong Xuan to search for the Queen Mother Grass, he himself hid at the bottom of the lake to cultivate the Heavenly Book Supplement. The Black Dragon's three thousand years of cultivated Mana were extremely robust and vigorous, but it had no spells to utilize, only able to spew its inner core to strike people. Now, with Daoist Techniques, Shi Feiyang practiced each of the thousand spells listed in it.
The book also contained Sword Refining Techniques & Refining Treasure Techniques. He took Sikong Xuan's Flying Sword for himself, re-refined it with methods from the book, then drilled the Sword Techniques detailed within until he was proficient and wielded them effortlessly.
As for Sikong Xuan, he ventured out daily in search of Spirit Medicines, gradually familiarizing himself with the routes and began plotting his escape.
He caught a pine crow in the mountains, arranged stones into a formation on the mountain, and performed a ritual with the crow at the center. Afterward, he released the crow, silently praying, hoping it would fly to Chongming Island and inform his uncle about his predicament, urging him to come to the rescue quickly.
Believing he could fool everyone, he did not realize the potency of the Heavenly Book Supplement. The Earth Immortal who compiled the book was a fierce figure from a side path, and his Prohibition of Primordial Spirit was different from the rest. Shi Feiyang used the Three Talents Mirror as the Magic Artifact specifically because the spell not only constrained the target's Primordial Spirit but also allowed him to see what the other party was doing from afar!
Everything Sikong Xuan did each day, where he went, and his every move was seen by Shi Feiyang through the treasure mirror.
Seeing the pine crow take flight in the treasure mirror, heading southeast, Shi Feiyang emerged from the lake and climbed to the peak top.
His dragon eyes had exceptional vision, capable of seeing ants climbing trees a thousand miles away. He quickly locked onto the pine crow, let it fly a distance southeast, and once sure that Sikong Xuan could no longer see it, he opened his mouth and inhaled.
The pine crow, already a hundred miles away, suddenly felt tight, locked by Dan Qi. Desperately flapping its wings trying to break free, it was involuntarily wrapped in the Dan Qi and shot toward the peak top at high speed.