According to Wu Shang's own experience, simultaneously drawing upon earth fiend qi and Qiantian astral qi to temper the core required a golden core that had not lost its vitality in order to withstand such a terrifying impact.
Qin Sang had obtained Daoist Jiupao's golden core a year ago, so only nine years remained before it lost its vitality from having been separated from a living body for too long.
If he wished to attempt Wu Shang's method, he had to do so within these nine years; otherwise, he would have to seek out a new golden core or demon core.
Dealing with Daoist Jiupao had already been an ordeal, to say nothing of other Golden Core experts.
Within the next nine years, this current window was likely his only opportunity. Once the matter of Ziwei Palace concluded and the spirit tide dispersed, the four Golden Core Masters of the Qingyang Demonic Sect would return to their mountain gate and would not easily leave again.
Although Qin Sang was using the Core Formation method left behind by Wu Shang, he had no desire to turn himself into a living corpse, making both an active golden core and Qiantian astral qi indispensable.
Yunyouzi looked deeply at Qin Sang. "It seems you've already thought this through... But have you considered what we will do about the Qingyang Demonic Sect's mountain-protecting grand formation, even if we make thorough preparations and barely manage to deal with that remaining Golden Core cultivator? Decades of effort were poured into personally laying down this formation by the founding patriarch of the Qingyang Demonic Sect, who once shook the Lesser Cold Domain, and it has kept the sect safe to this day. Even though the Qingyang Demonic Sect has declined, none of the other demonic sects have dared to set their designs on it, largely owing to this grand formation."
Qin Sang had laid low in the Qingyang Market for so long that he had thoroughly investigated the sect's background, and this mountain-protecting grand formation was something he had heard about many times over.
It was said that when the last Nascent Soul cultivator of the Qingyang Demonic Sect passed away, two Nascent Soul cultivators from other demonic sects received word and joined forces to storm the mountain gate, pushing the Qingyang Demonic Sect to the brink of ruin.
The one who took over as sect master of the Qingyang Demonic Sect was merely a late Golden Core cultivator, yet without seeking outside aid, he simply activated the grand formation, holding the mountain gate steadfast and forcing the two Nascent Soul cultivators to return empty-handed.
After their departure, both Nascent Soul cultivators maintained complete silence regarding the battle.
From then on, the Qingyang Demonic Sect's mountain-protecting grand formation became renowned far and wide.
Against such a formidable mountain-protecting grand formation, Qin Sang and a hundred more Yunyouzis combined could never break through by force. It was precisely because of this that Yunyouzi had raised the question.
The Qingyang Demonic Sect's mountain-protecting grand formation was the greatest obstacle.
If they could not enter the Qingyang Demonic Sect, all else was out of the question.
"We must think of a way to get the two of us inside..."
Yunyouzi paced back and forth, racking his brains on Qin Sang's behalf, finding the dilemma deeply vexing. "The situation in the Yuncang Great Marsh has settled now. The various sects are no longer on edge like before, but neither will they let down their guard. Especially with the Qingyang Demonic Sect Master away, they will certainly be even more vigilant and will not easily allow outsiders onto the mountain. Unless, Brother, you know someone close to the Qingyang Demonic Sect who could bring the two of us in, after which we could find a way to avoid their sight and sneak into the inner sect..."
Qin Sang shook his head. "Do not worry, Senior. I have thought of a method that stands a good chance of slipping into the Qingyang Demonic Sect. If it fails, I will find another way. Furthermore, Senior, you do not need to sneak into the Qingyang Demonic Sect with me. I would like to ask you to take a Qingfu coin to Wuya Valley..."
As he spoke, Qin Sang retrieved two copper coins from his mustard seed bag.
One of the copper coins was large and the other small, with the smaller coin nesting neatly inside the center of the larger one.
When fitted together, one could see two Qingfu spirit insects, large and small, carved upon them—a mother and child, rendered vividly down to the finest detail.
The mother was on the outer coin, while the child lay in the center.
These Qingfu coins were special magic tools refined using the blood drawn from spirit insects known as Qingfu. The mother's blood was smeared onto the mother coin, and the child's blood onto the child coin.
Two cultivators would each hold one, one keeping the mother coin and the other the child coin.
When the holder of the child coin crushed it while activating the insect blood with spiritual power, the mother coin would resonate and produce a new child coin.
Naturally, there was a limit to the distance between the two Qingfu coins, but their range was quite vast—even with Qin Sang at the Qingyang Demonic Sect and Yunyouzi at Wuya Valley, the connection could still be felt.
The function of the Qingfu coins was somewhat similar to the Concentric Pendants Yunyouzi had given them back in Xihuang Town. Though not quite as versatile since they could not transmit messages, they likewise remained unimpeded by various restrictions and formations.
So long as it was within the range of the Qingfu blood's resonance, crushing the child coin would trigger the mother coin.
The advantage was that the range of the Qingfu coins was greater than that of the Concentric Pendants, and unlike the pendant, which was ruined once crushed, the child coin could regenerate repeatedly until the mother blood was exhausted, allowing it to be reused several times.
The Qingfu was a spirit insect; while not as peerlessly rare as extraordinary insects like the Fire Jade Centipede, it was still very scarce and difficult to find.
This set of Qingfu coins had not been refined by Qin Sang. It was spoils of war he had acquired by chance during a fierce clash with the Heaven-Traversing Alliance in the Luandao Waters. Seeing its peculiar efficacy, he had deliberately held onto it.
The coins had already been used multiple times, and little of the mother's blood remained, leaving enough for only three or four more uses.
Qin Sang handed the mother coin to Yunyouzi while keeping the child coin. "The Qingyang Demonic Sect is very close to Wuya Valley, and most disciples of the sect train there. Once I crush the child coin, I would like to ask Senior to find a way to stir up some trouble for the Qingyang Demonic Sect's disciples and draw their attention away. If that Golden Core cultivator can be lured out of the mountain gate, that would be even better."
Qin Sang had faith in Yunyouzi's strength.
His magic tool, the Flawless Pearl, was truly miraculous.
Qin Sang had noticed that the Flawless Pearl grew stronger alongside the rise in Yunyouzi's cultivation. Back when Yunyouzi was only at the middle Foundation Establishment stage, the Flawless Pearl had already been quite extraordinary; now, it was surely even more formidable.
Qin Sang sensed that this was not even the full extent of Yunyouzi's power.
To infiltrate the Heavenly Demon Mound and emerge unscathed made Qin Sang find him all the more unfathomable.
Qin Sang judged that without employing the Flying Yaksha, he himself lacked complete certainty of defeating Yunyouzi.
The Foundation Establishment disciples of the Qingyang Demonic Sect were certainly no match for Yunyouzi. Only Yunyouzi could handle such a task; Mu Yifeng, Senior Brother Rong, and the others fell short.
The most dependable candidate would naturally have been Qi Yuanshou, but for one, Qin Sang had no opportunity to ask, and for another, Qi Yuanshou would certainly interrogate him thoroughly and never permit Qin Sang to degenerate into the corpse path.
Taking the Qingfu coin, Yunyouzi clearly disapproved of Qin Sang's plan. He frowned and questioned, "Are you planning to run amok in the Qingyang Demonic Sect? How do you expect to escape then?"
Qin Sang shook his head. "Unless driven to absolute desperation, I will not force my way through. Luring away that Golden Core cultivator is merely to buy as much time as possible."
Yunyouzi's expression eased slightly as he mused, "Luring the tiger away from the mountain, is it...? With three of their Golden Core cultivators gone, it will be when the Qingyang Demonic Sect is at its most vulnerable, so they will certainly be exceedingly wary. If this old Daoist only makes moves against the disciples of the Qingyang Demonic Sect, it would be far too conspicuous and leave traces behind. Once they realize someone is targeting them specifically, they will only become more vigilant. As long as that Golden Core cultivator isn't a fool, he won't fall for it easily."
Qin Sang sighed. "If it cannot be done, it cannot be forced. So long as you can tie up their attention, my purpose will have been achieved."
Yunyouzi nodded, and then his eyes suddenly lit up. He muttered in contemplation, "Worry not, Brother Qin. This old Daoist knows what to do..."
Chapter 505