The next ingredient didn't wait very long. This time, Cao Yun was extremely careful. Instead of taking the ingredient directly from his spatial ring, he took a large box. It was made of Bright Fallen Oak. The Bright Fallen Oak was a tree primarily used by the Sutra Faith. Indeed, it was very precious and used solely during ceremonies and for various important items. For many, it was considered a sacred tree. Most people thought that this tree could soothe the souls of the dead and help them reach the Heavenly Court in order to be reincarnated faster than usual.
Honestly, Cao Yun wasn't sure about any of those myths. However, he could clearly tell that this tree had a calming effect on both Death Energy and Ghost Energy. As a matter of fact, it had almost no effect whatsoever on souls when they were alive, only after death. Although it was strange, Cao Yun had met many strange things. Besides, it proved to him that although souls were made of the same stuff as Death Energy and Ghost Energy, their nature was different. Just like a dead body was made of the same material as living flesh, but was fundamentally different. Death was altering something essential while not changing the nature of the elements within. Cao Yun would need to study the Dao of Death further to understand it fully.
All the alchemists were in awe when they saw the box. Indeed, it was almost as large as the cauldron itself. Cao Yun had probably carved an entire Bright Fallen Oak tree in order to make this box. As a matter of fact, he had. Cao Yun had literally built this box from one singular Bright Fallen Oak tree. Even with the tree, which was considered purifying and a 5-star Heaven ingredient, and even with many runes inscribed all over the box, they could all feel a terrifying aura.
It was as if the box contained a wild animal that only wanted to slaughter them all. Some alchemists saw images of their own bodies ripped to shreds by some dark creatures attacking them in the night. All their cultivation was meaningless. They were like mortals before an evil creature, like children terrified of some folktale monster. However, they all knew that this monster was real. Indeed, it was obviously the aura of the Nine-Headed Bird of Chu. If they had faced that demonic beast, they would have been annihilated body and soul. None of them stood a chance against such a monstrous existence.
Cao Yun had prepared the ingredients so that no alchemist could recognize the beast. Even its head had been carved and processed. Besides, the Nine-Headed Bird of Chu wasn't a very notorious demonic beast. No one had actually seen it in real life, of course. But no one had seen detailed illustrations either. Although they could tell some properties of the demonic beast, they didn't suspect which creature they were dealing with. Honestly, it was a risk as Cao Yun didn't want the news to reach Emperor Weide. From this information, he might be able to deduce certain things. Hopefully, it wouldn't matter...
Xiao Xuefeng was ready, but Cao Yun gave Sun Liao some time. His brother knew about the Nine-Headed Bird of Chu and about the refinement process. As such, he knew precisely what was within this box. And this wasn't the worst part yet. Sun Liao spent almost a double hour preparing the array formations. A few pills were distributed among the alchemists, and many wanted to keep watching but were too exhausted. So they used pills to recover faster. The pills were so close to success, they couldn't leave just before the end. History was being made, after all. Even if their life was actually in danger, they didn't care, they had to see it through to the end. Among them, Mei Hua and Feng Yingyue were also adamant that they wouldn't leave their brothers. On the other hand, Song Guixiang had already left some time ago with two beauties. There was absolutely no doubt in anyone's mind about what he was doing.
Despite his fatigue, Song Guixiang had found enough strength to entertain himself. Director Hua was focusing on the refinement, but she noted his absence. There would be hell to pay for the plump man. Hopefully, those two beautiful women were worth it. Throwing away such an occasion to deepen his alchemy was a sin in Director Hua's eyes. If she had enough strength and enough time, she would have stormed into his chambers and brought him here herself, no matter which state he was currently in. Thankfully for everyone, no one would have to see such a show.
Finally, Cao Yun got a signal from Sun Liao. He opened the box.
The hostile aura spread like wildfire. Sun Liao's array formations shook. The flames and the cauldron itself shook. Although it was around noon, the world suddenly seemed dark. Even the Sun couldn't pierce through this hostility. Some alchemists were able to see through the terrifying aura. Before their eyes could tell them what the ingredient was, their ears did first.
Everyone heard a rhythmic thumping sound. Their hearts skipped a beat as they realized that Cao Yun had produced the heart of a 9-core demonic beast. Although the creature was dead, the heart was still beating. Cao Yun had literally carved a small array formation within the organ so that it would keep all of its vitality. As such, it was still pumping. Besides, Cao Yun had trapped some blood, and more than that, some blood essence, within the heart. As such, it was pumping this blood into itself, going from chamber to chamber. In other words, it was as if the alchemists were observing the heart of a living demonic beast.
Inside the Thirteen Celestial Pyre, the five pills reacted to the heart. Immediately, they tried to leap from the cauldron. Xiao Xuefeng was ready and blocked them all. However, they were already causing a great strain on the alchemists trying to stop them.
Without a moment's delay, Xiao Xuefeng sent tongues of fire into the beating heart. The flames went through the aura of hostility and reached the heart. However, waves of Death Energy assaulted Xiao Xuefeng's spiritual senses. As she was the most talented when it came to souls, Xiao Xuefeng was able to contain it, but it was incredibly difficult and even painful. From above, Cao Yun was doing everything he could to prevent the Death Energy from leaving the heart, but he didn't want to reveal his full cultivation and understanding of the Dao of Death. With it, he could have easily suppressed it all, especially with all the runes he had carved into the heart.
That being said, Cao Yun's presence made Xiao Xuefeng's work easier. Moreover, he had told her what to expect and she was fully ready for it. Although it was difficult, there was nothing unexpected. She was more or less controlling the souls of all her team. As such, they were all feeling the pain. Everyone could tell that their faces were deformed by pain. If Spirit Warriors were showing pain, it proved how terrifying the experience was.
After several hours, the heart was fully infiltrated by the flames. Not a single spark was visible outside. Slowly, the flames replaced the blood within, consuming the blood and then even the blood essence. It didn't take long for the organ itself to be consumed. Xiao Xuefeng was very thorough. Only once she made sure that everything had been consumed did she try to open the lid of the cauldron. But once her decision was made, she didn't hesitate.
The very moment she opened the lid, all five pills tried to leap out. One almost succeeded. It was technically outside the cauldron for an instant before the alchemists dragged it back in. Sun Liao was ready to act, but didn't have to, this time, at least.
As fast as she could, Xiao Xuefeng directed the flames into the cauldron. All the medicinal essence from the heart was now contained within the tongues of fire. Each one was a different shade, but they were all golden and crimson as blood. Xiao Xuefeng could tell that every single strand of fire had a variety of properties. So she had to choose very carefully among thousands of sparks, which one to use for which pill.
With Cao Yun's plan in mind, she began. The very first thing she did was to find where the Shattered Soul Hellbloom was. Indeed, Cao Yun had mixed it into the blood inside the heart and into a few runes. After all, they knew that the massive hostility from the heart would completely mask the poison. Neither Cao Yun nor Xiao Xuefeng could detect it, even knowing that it was inside. Now, it was inside the flames Xiao Xuefeng would use to inscribe the eighth circles. Using Cao Yun's methods, she was able to find all the flames containing the poison. Afterward, she began to work on the inscription.
Stroke by stroke, Xiao Xuefeng inscribed the eighth circle on the very first pill, making sure it stayed the best pill possible and using all of the poison. After almost two days, she was done, but she still had four other pills. Instead of keeping the most unstable pill for the end, she worked on it second. Her team was surprised but went with her decision without questioning it at all. They didn't even try to guess her reasoning. Cao Yun knew it all too well. Xiao Xuefeng hoped to salvage this unstable pill by working on it while she was at her best, before the fatigue overcame her.
Unfortunately, this unstable pill was almost falling apart. Each stroke of the flames was creating minuscule cracks on the surface of the pill. If a crack caused the Netherstill Soul Steel and the Ninefold Warm Spirit Grass to come into contact with one another directly, the pill wouldn't just fall apart. It might actually explode with extreme violence. In other words, it could endanger all the other pills. With all that in mind, Xiao Xuefeng refused to let it go to waste. Many alchemists had poured in their very best, she had to salvage this pill. However, she wasn't stupid. Before trying to do anything, she put several layers of protection between this unstable pill and the others. By altering the temperature of the cauldron at key points as well as the very properties of the flames and even the composition of the medicinal essence within the cauldron, she made sure that the fifth pill was isolated.
Even if it exploded, it could be contained. Obviously, Cao Yun watched it very carefully. He had to admit that Xiao Xuefeng was impressive. She had taken the Five Element Wheel into account as well as Yin-Yang Balance. But she also had a subtle understanding of the Sixty-Four Multitudes and the Ten Thousand Creations. The yin and the yang could produce many alterations of nature. When combined with the five elements present in everything, they could lead to infinite outcomes, those were the Ten Thousand Creations.
Besides all of that, Xiao Xuefeng began to use Treasures in Mud. This principle was simple to state but almost impossible to practice in difficult situations. Any ingredient could be replaced with other ingredients as long as all the interactions between ingredients were similar. Xiao Xuefeng was trying to use medicinal essence within the cauldron to fill the cracks in the pill. As such, she had to try and imitate the interactions between Netherstill Soul Steel and Ninefold Warm Spirit Grass. Cao Yun was observing it and was awed by Xiao Xuefeng's expertise. Thanks to him giving her the complete recipe and a detailed analysis of the refinement process, she had been able to find many ways to repair the pills. Although she hadn't found real alternatives to Netherstill Soul Steel and Ninefold Warm Spirit Grass, she had found ways to stabilize their interactions as long as there wasn't too much damage. She couldn't repair huge cracks, but she could absolutely fill those tiny ones.
While she was working on this fifth pill, she had other alchemists begin their work on the three remaining pills. Thankfully, they didn't have to inscribe the most minute details, they simply focused on the foundation of the eighth circles. Thus, it wasn't too difficult for them. That being said, she kept an eye on them. In a sense, it was as if she had split her own soul into several parts as they were all forming one large soul together. In a way, she had asked her left arm and right arm to do something else while she was focused on a task that required her full attention.
After three days, the fifth pill was done. It would never be neither a Pure nor a Perfect pill, but it could be successful. In fact, it might actually be very close to a Perfect pill. Honestly, Cao Yun was impressed. If it had been him, he might have just given up on this fifth pill altogether. But Xiao Xuefeng realized how important each pill was. No matter how poor it was, any 5-star Spirit pill that succeeded was a priceless treasure. Moreover, those pills could actually help cultivators break through to the Sage realm. So she wanted as many pills as possible.
In her mind, it was obvious that three of those pills would go to Emperor Weide, Sect Leader Xuan, and Matriarch Huang. After all, they were all 9th-grade Spirit Warriors. That meant that they needed at least four pills so that Cao Yun could use one. Indeed, Xiao Xuefeng found it natural for Cao Yun to get one for himself. But that meant that they needed to refine five pills if they wanted to keep one. Honestly, Xiao Xuefeng still wasn't sure who should have this pill. Deep down, she obviously wanted it for herself, but she wasn't confident that she could actually break through, even with the pill's help. As such, it might be more intelligent to keep it for someone else.
If someone was ready to break through, they could give them the Nine-Souls Calamity Ascension Pill. Xiao Xuefeng and Director Hua absolutely wanted to refine five pills. But they wouldn't endanger the entire process for that, either.