The Myriad Ghosts Cavern lay directly beneath the Grand Hall of the Arctic Celestial Emperor, but the stone cottage marking its entrance was situated diagonally behind the hall, on the northern slope of the mountain.
The cottage was built entirely of heavy granite blocks, its solid timber door measuring a full foot thick. Both the door and the stone walls were carved all over with countless talismans.
On this northern slope, sunlight reached the cottage only on summer afternoons, and the heavy stone walls blocked out what little daylight there was, leaving the rooms dim and chilly.
Inside was an enclosed, standalone room from which an underground tunnel led straight down into the Myriad Ghosts Cavern.
Zhou Wuji had visited the cavern once before, and this cold, sealed stone cottage had left a deep impression on him.
Returning this time, he, Martial Uncle Yiping, Yang Tieying, and Shangxing were going to take up permanent residence here.
Though secluded, Feixuan Hall had been a proper grand hall, fully equipped with furnishings and daily utensils, complete with its own private courtyard, making it quite comfortable to live in.
The stone cottage also had a courtyard, but it was small and bare, paved with thick flagstones without so much as a blade of grass.
Daoist Yiping naturally sighed and groaned, while Shangxing and Yang Tieying wore miserable scowls.
Moving from Feixuan Hall to this stone cottage felt like plunging from heaven into a ditch. Such a staggering contrast made it hard for them to adjust.
Zhou Wuji, on the other hand, found it decent enough. The stone cottage had four rooms, giving both him and Yiping private bedrooms, and the courtyard featured an independent kitchen and latrine.
Beside the kitchen, dry firewood was neatly stacked, allowing them to kindle fires, cook meals, and boil water to meet their daily needs.
Zhou Wuji could hardly lecture Martial Uncle Yiping, so he scolded the two youngsters instead, preaching grand platitudes like "a sword's edge is honed on the whetstone, and the plum blossom's fragrance blooms from the bitter cold."
Yang Tieying and Shangxing were young after all; Zhou Wuji's fiery words stirred their blood, and they soon rallied their spirits.
Daoist Yiping chuckled from the side without a word. At his age, he naturally was not swayed by Zhou Wuji's preachings, but he felt this was for the best.
Vigorous youngsters were far better than a group moping around with funeral faces.
Besides, Zhou Wuji was not deceiving them.
For the two boys, staying at the Myriad Ghosts Cavern was indeed fine tempering—provided they had enough pills to dispel the yin fiend qi so their bodily foundations would not be harmed.
Tempered well, ordinary people could draw out their latent talents; tempered poorly, even a genius could be ruined.
The crux lay in grasping the proper measure and timing.
According to regulations, guardians stationed at the Myriad Ghosts Cavern were allocated Golden Yang Pills. Even a First Revolution Golden Yang Pill was of immense benefit to cultivators.
It was precisely for this reason that people were willing to take on the bitter duty of guarding the Myriad Ghosts Cavern.
Yet when Daoist Yiping and the others arrived for their rotation, they received no Golden Yang Pills at all.
Zhou Wuji did not know whether the Controller had been negligent or if Daoist Yiding and his faction were deliberately making things difficult for him.
Intra-sect strife was sometimes just that crude and direct. It was through the continuous accumulation of petty grievances like these that the Seven Lineages came to treat one another like mortal enemies.
Zhou Wuji had never refined Golden Yang Pills before, but fortunately, he had learned the formula from Wuzheng.
The Golden Yang Pill was of an extreme Yang nature, specifically tailored to purge yin fiend qi. While it fortified the spirit and strengthened the body, its medicinal properties were overly fiery and fierce.
Its scope of application was narrow, yet concocting it was rather intricate; to Wuzheng, brewing Golden Yang Pills was hardly worth the trouble.
Given the current circumstances, there was no telling when they would ever receive their share of Golden Yang Pills.
With his superb cultivation and rock-solid foundation, Zhou Wuji could neutralize all yin fiend qi through the Northern Dipper Celestial Pivot Scripture alone.
Daoist Yiping would be fine for a short while, but over an extended period, it was hard to say.
Considering everyone's welfare, Zhou Wuji asked Wuming to help him purchase a batch of medicinal herbs.
Wuming was well-connected and carried enough clout when shopping outside that she would not be swindled.
He still had more than two thousand taels of silver on hand, which was ample to buy the herbs.
Hearing that Zhou Wuji had been rotated to the Myriad Ghosts Cavern, Wuming was deeply indignant on his behalf, but powerless to change it, she could only vent a few grievances alongside him...
Zhiyuan had departed, but fortunately Yizhen's name still held considerable weight in Yunyang City. Two days later, Wuming had the herbs delivered.
Four yellows, four mushrooms, eight minerals, seventy-two herbs, plus certain special metals and minerals—all told, well over a hundred varieties of ingredients.
Zhou Wuji possessed formidable divine sense and had thoroughly studied books such as the Green Pouch Scripture, the Compendium of Materia Medica, and Dan Jing Yao Li, etching their contents deep into his memory.
His grasp of medicinal substances and their properties now far surpassed Wuzheng's, and paired with his practiced alchemy techniques, refining Golden Yang Pills was not especially difficult.
Zhou Wuji attempted a trial furnace first. The heat regulation was slightly off, and during the elixir completion stage, it failed, reducing the ingredients to dregs.
He learned his lesson: blind confidence was ill-advised. He opened the Northern Emperor's Book of Heavenly Punishment.
Applying a destiny pattern worth just over one tael to the Golden Yang Pill, he elevated his mastery of it to the Proficient level.
Firing the furnace once more, Zhou Wuji successfully turned out a batch of Golden Yang Pills—all at the First Revolution rank, a full hundred and twenty in total.
The pills possessed a scorching medicinal heat. Even while stationed right at the entrance to the Myriad Ghosts Cavern, one pill every five days was enough for Yang Tieying and Shangxing.
As for Daoist Yiping, one every half month sufficed.
Having taken five days to craft this furnace of Golden Yang Pills, Zhou Wuji felt his worries ease.
He had no fears for himself; he only worried the two boys might not withstand the yin fiend qi and would ruin their foundations.
In just a few days, Yang Tieying was fine thanks to his robust vital blood, but Shangxing had not yet reached Qi Ingestion, and his small face had already turned somewhat pale and purplish.
Once a Golden Yang Pill was swallowed, Shangxing's little face immediately flushed with rosy color, the trace of yin fiend qi that had accumulated inside him swept away completely.
Yang Tieying was even more restless with excitement after taking the pill. He went out into the courtyard and practiced two rounds of fist forms with snapping crackles, thereby releasing the pill's potency until he felt clear and unblocked inside and out, thoroughly invigorated.
Daoist Yiping stroked his beard and smiled from the side. After days of living here, the courtyard finally had some lively spirit for the first time.
In truth, he had been harboring bitter resentment. Guarding the Myriad Ghosts Cavern was bad enough, but having their Golden Yang Pills withheld was infuriating.
Yet he dared not complain to Zhou Wuji; he knew Zhou Wuji was ruthless and unsparing, and stirring up a fuss over such a petty matter simply was not worth it.
Zhou Wuji understood Daoist Yiping's feelings as well. He held nothing but contempt for the Yuheng lineage's conduct, yet he was not particularly angry.
Zhiyuan had spoken at length before leaving, and Zhou Wuji had taken his words to heart.
Most importantly, he genuinely liked the assignment at the Myriad Ghosts Cavern and did not want to lose such a fine post by kicking up a row.
It happened that this tied into the Northern Emperor's Book of Heavenly Punishment, something he could not explain plainly to Martial Uncle Yiping.
His haste in refining the Golden Yang Pills had also been partly intended to make things up to Martial Uncle Yiping and the two boys.
With this pressing, vital matter resolved, Zhou Wuji set his mind at ease and led Yang Tieying down into the first layer of the Myriad Ghosts Cavern.
The last time Zhou Wuji had come here was back in the tenth month of last year, when he had slain several baleful ghosts.
These baleful ghosts condensed from yin fiend qi, gathering stray yin spirits of heaven and earth to birth a sliver of sentience; like wild weeds in the mountains and forests, no matter how many were purged, they could never be eradicated.
Yang Tieying's vital blood was surging and he had not learned to rein it in, so before walking far on the first layer, he drew the attention of an Eighth-Rank fierce ghost.
The ghostly silhouette was ethereal and flickering. Facing a yin spirit for the first time, Yang Tieying hesitated, his hand gripping his longsword tightly.
Zhou Wuji smiled. "No need to fear. Even a Seventh-Rank baleful ghost would have a hard time harming you. Surge your vital blood and hack it down."
Encouraged by Zhou Wuji, Yang Tieying gathered his courage, stepped forward, and cleaved downward with his sword. The crimson ghostly silhouette split apart upon impact.
Though there was no true qi on the blade, the vital blood surging around Yang Tieying boiled like fire, cleaving through the ghost and scorching it into black smoke...
Yang Tieying was thrilled. This triumph vastly bolstered his confidence and showed him the vulnerability of fierce ghosts.
Zhou Wuji guided Yang Tieying around the first layer, slaying several fierce ghosts, including one baleful ghost.
Letting Yang Tieying get some practice in the cavern, thick with yin fiend qi, would strongly stimulate his vital blood while keeping his mind in a state of sharp focus.
After slaying the baleful ghost, Yang Tieying suddenly shuddered throughout his body. Concentrating his mind naturally through the sword art, he actually breached the divine aperture between his brows, establishing a connection with the astral power high above the Nine Heavens.
A wisp of astral power descended, coursing through Yang Tieying's body before returning to the divine aperture, causing it to stabilize completely.
Zhou Wuji was somewhat astonished. The yin fiend qi in the Myriad Ghosts Cavern was dense, mingled with earthly fiend qi, which interfered with various spiritual qi, including astral power.
Yet this nominal disciple of his had actually condensed his divine aperture in the Myriad Ghosts Cavern, stepping into the Qi Ingestion realm.
Evidently, the lad possessed extraordinary talent in refining qi—surpassing his own by who knew how much.
It was merely that he had practiced martial arts in the past, and shifting to qi refinement had been impeded by his dense, heavy vital blood; this time, confronting yin spirits in the cavern, the intense focusing of his mind had successfully formed the divine aperture.
Naturally, the stimulating efficacy of the Golden Yang Pill played a part as well.
Observing Yang Tieying's transformation through the Heart Mirror, Zhou Wuji felt quite touched and reflective.
Had he not possessed the blessings of the Northern Emperor's Book of Heavenly Punishment, who knew how long it would have taken him to reach this stage?
Watching Yang Tieying link with the astral power above the Nine Heavens, the entire process seemed effortless and natural, a true unity of Heaven and man, yet extraordinarily intricate and subtle.
Zhou Wuji had undergone this experience several times, but back then he had been focused entirely on his own internal shifts.
Watching from the side now, he could take in the full spectrum of his disciple's vital blood and true qi shifts, as well as every nuance of the resonance with Heaven and Earth's astral power.
Through this comprehensive observation, Zhou Wuji noticed an issue: his past understanding of astral power had been somewhat skewed.
The stars lay high above the Nine Heavens, like the sun and the moon.
Out of habit, he had naturally assumed that astral power beamed down from the Nine Heavens, piercing through heaven and earth, just like other forms of spiritual qi.
Yet from what he perceived this time, astral power was not simply beamed down; it permeated the eight directions, blanketing heaven and earth, present everywhere.
In the understanding of a Daoist cultivator, astral power was an unimaginably vast domain of law—so immense it was immeasurable.
By extension, various kinds of spiritual qi were countless overlapping law domains, weaving together the very order of this world.
Cultivators within these layered law domains primarily sought to eliminate all manner of interference, using divine sense to resonate with the vast domain of law rather than dwelling on whether astral power was being projected down or not.
At this moment, Zhou Wuji sensed that he had truly made progress—a progress born of a profound understanding of heaven and earth, rather than originating from the blessings of the Northern Emperor's Book of Heavenly Punishment, even if there was no substantial difference between the two.
He recalled Zhiyuan's words again: art and techniques, in the end, fell far short of the heavenly origin.
Formidable as the Tianji Sword was, it remained merely an art for wielding true qi; compared to the Northern Dipper Celestial Pivot Yin Thunder, it was a whole tier below.
Zhou Wuji had been weighing this over the past several days, and now he finally made up his mind: upon returning, he would invest five taels and six qian of destiny pattern to upgrade the Northern Dipper Celestial Pivot Yin Thunder.
For a method that pointed straight toward the Great Dao, no amount of investment was a waste.
"Master, I think I've ingested qi!"
Yang Tieying snapped awake from his qi ingestion and shouted excitedly at Zhou Wuji.
Zhou Wuji nodded slightly. "'A sword's edge is honed on the whetstone'—that is the very principle at work here. Now that you've been ground a little, hasn't it succeeded? Hone yourself well a bit longer, and advancing to the Seventh Rank will be right around the corner..."
Yang Tieying nodded vigorously. "I will temper myself diligently and never disappoint Master's high hopes!"
Then, turning around with utmost sincerity, he praised, "What Master says is truly wise counsel—words of sheer wisdom!"
He had wanted to sing his master's praises, but after racking his brains and coming up with no better words, he could only repeat, "Words of sheer wisdom!"
The last time, he raised his voice, practically bellowing it.
Zhou Wuji broke into helpless laughter...
Chapter 119