Since he had nothing better to do, Cao Yun focused almost entirely on two things, his blood cultivation and his mind cultivation. The more urgent matter was in fact his blood cultivation. But extracting his Unclean Evil and improving his Drop of Wrath would have positive outcomes on both his ability to help Dian Mo and his blood cultivation. Indeed, the properties of the Drop of Wrath were spread throughout his entire body already.
Just as he was cultivating, Hongyu was also growing stronger. Now that she had five demonic cores, she was stabilizing her cultivation. Unlike humans, it was instinctive. But through Cao Yun's help, her condition got stable earlier than it would have alone in the wild. As such, in less than two months, she was a full-fledged 5-core demonic beast. And since she had finally formed a demonic core full of the properties of the Drop of Wrath, it was able to balance out her evil core. In other words, she could use the Evil Qi to some degree, making her more powerful than an ordinary 5-core demonic beast. Besides, she was able to fly, which would give her an edge in many fights.
If the two of them worked together, they might kill the slavers. However, if this wasn't planned properly, they would also be heavily injured. After all, they had fought against a 7-core demonic beast. Although they were not good fighters, they were very competent when it came to working together against a common enemy. Anyway, Cao Yun was already planning their deaths if need be. While they were busy leading the caravan through the Desolate Dune Desert, the fake Accomplished Demon was cultivating and growing stronger.
By overhearing some conversations, he learned a bit more about the region he was in. In fact, he also heard rumors about the attack prepared by the Empyrean Asura Theocracy. If rumors of preparations were reaching this place, there were high chances that almost no time had passed since Cao Yun had gone through the bleeding space. Considering how far they were, Cao Yun was trying to guess how long it would take for news of the actual attack to reach them. Because it had not yet, it meant, at the very least, that Cao Yun had not spent years in the bleeding space. Most likely, he had spent either months, weeks or even days. Of course, time had felt different for him but since space had been completely distorted, this was to be expected.
Anyway, he also learned that their continent was surrounded by the Divine Blood Ocean. Every time they talked about it, they emphasized how dangerous it was. The few ships sailing on that Divine Blood Ocean were manned by at least one late Accomplished Demon. And the ship itself was also protected by 8 or even 9-core demonic beasts. Although Cao Yun didn't know of the threats lurking in that Divine Blood Ocean, he could imagine what kind of demonic beast could live in the abyss. That was very bad news for him. If the only way to leave this continent was through that Divine Blood Ocean, he would either need to get a powerful crew to help him or become a late Accomplished Demon himself. None of those options would take him a short time. In other words, he might stay stuck on that continent for years before he could go back.
The only other alternative would be to pierce through space. But for that, he would literally need to become a Sage or a half-step Sage at the very least. Even the Empyrean Asura had not been able to fully form a door toward the Imperial City. And for that, he had sacrificed a 9th-grade Spirit Warrior. Thus, Cao Yun had almost no hope of achieving that, no matter how talented he was with array formations and blood runes.
On their way to Yixin City, the caravan stopped several times. The slavers knew this place enough to avoid most of the powerful demonic beasts. Their encounter with the Tyrant Sun Scarab had truly been bad luck. In the few months Cao Yun spent with them, they were clearly competent. Without them, Cao Yun had to admit that his chances of surviving the Desolate Dune Desert were slim. Even a late Accomplished Demon would not treat this desert lightly. After all, a 9-core demonic beast could attack out of nowhere all of a sudden. Without a deep knowledge of this place, crossing it would be near impossible.
Even with his compass, Cao Yun would probably need more than a year to find his way out while always being on the lookout for threats. Unfortunately, he had to keep the slavers alive. Because of that, he had to disregard the torment and humiliation visited upon the slaves. Since they needed the men to pull the caravans, the slavers never left any debilitating or lasting damage on them. And because they wanted to sell the other slaves, they didn't mistreat them too much. However, they were cruel even though the slaves were fellow demons. Since they were merely Blood Children, they needed water and food much more than the slavers. Thus, they often enjoyed tormenting them with those. Several times, they even proposed Cao Yun to play around with one of the women as long as he didn't damage her. Of course, Cao Yun refused and ordered them to leave him in peace.
The more he was in contact with them, the more he wanted to exterminate them all and the more he was ashamed of himself for allowing them to persecute their victims. However, he kept telling himself that he no choice. He needed them to get out of this Desolate Dune Desert. If only Dian Mo was fully conscious, he might help him out with that. By performing a Soul Memory Search on them, he wouldn't need to keep them alive at all and could free the slaves. But then, he had no idea what he would do with those slaves. He couldn't just leave them alone in the desert.
After less than two months, Cao Yun finally broke through. His Mingmen vibrated. Visualizing his kidneys as a golden palace, the Golden Fate was pulsating all around. His blood and marrow were rich and plentiful in his Lower Dantian. Naturally, they both overflowed in his entire abdomen. He could feel a powerful vitality. In fact, if his meridians had not been strong enough, they would have been consumed by this new blood mixed with his marrow. But since they were strong enough, his meridians were already being tempered. Usually, it should have been possible only as a 5th-grade Mortal Warrior. However, there was already a lot of Fire Qi in his own blood to perform the tempering.
Thus, Cao Yun was cultivating both the 4th-grade and 5th-grade of the Mortal Warrior realm at the same time. While he was still accumulating Fire Qi in his Middle Dantian, his blood was tempering his meridians. However, he still decided to focus on his blood cultivation for the time being. Indeed, he was a bit afraid of showing his meridians. And tempering them while hiding them with 'Ashen Feather Seal' was difficult. Besides, the slavers were clearly suspicious of him. After all, he had spent the entire time isolated in that empty caravan, even refusing the many offers they had made to him.
Of course, all Accomplished Demons were not depraved to the point they would abuse any slave they could. Still, his behavior felt odd to the slavers. After all, they were used to dealing with Accomplished Demon in their business. But the aura surrounding Cao Yun was clearly the one of a demon who had awakened his Flying Poison. Only a 1st-grade Accomplished Demon could do such a thing.
After performing 'Life Gate Reveals the Treasure', Cao Yun could now clearly feel some kind of tiny flame in his kidneys. The next stage would be 'Treasure Covered in Blood'. In simple words, it consisted in using this Kidney Fire to merge both blood and marrow in order to create the Golden Blood. That was a very important step in asura cultivation. After all, once formed, the Golden Blood could only be altered at a high price. Indeed, the blood essence and the marrow would fuse. Separating them afterwards was almost impossible. To put it differently, forming one's Golden Blood could be fought of as a form of tribulation.
There was no risk in forming one's Golden Blood. But its quality would then determine how fast and how far a demon could go. Such a step was a deciding factor on a demon's future. Thus, Cao Yun had no intention of botching it up. According to the slavers, they had at least three more months before reaching Yixin City. If they had had powerful demonic beasts to pull the caravan, they could have moved a bit faster. At some point, Cao Yun even thought about asking Hongyu, but this would affect the way the slavers saw him. Even secluded, he could tell they were becoming suspicious of him.
Cao Yun's Kidney Fire was rather weak at first. But with his knowledge of alchemy and with the Rune of Fire, it wasn't difficult to improve it. In fact, he literally used his Black Heart Flame to increase both its quality and its strength. Since this Kidney Fire was responsible for turning Jing into Qi, by improving it, it would also improve one's vitality. Moreover, the Kidney Fire would also alter the quality of the Qi. By now, Cao Yun's Qi contained traces of the Black Heart Flame in it. That was to say that Cao Yun's Qi had traces of Death Energy, strangely altered. Death Energy was after all related to Jing as was the Po.
This was also a good thing for his mind cultivation. And since the Rune of Fire was engraved in the Drop of Wrath, Cao Yun was focused on strengthening it by developing his Unclean Evil. In order to do that, he concentrated his mind and will on his feeling of shame. Ironically, using his shameful behavior to feel his shame was making him even more ashamed. Deep down, he felt though he was benefiting from abandoning those poor slaves to their fate. Thus, he could clearly feel his Unclean Evil mixed in with his own Po.
Just like he had done with his Flying Poison, Cao Yun was carefully extracting each strand of Unclean Evil from his Po character. Bit by bit, he was forming a cloud of bone dust around the Po character. But unlike the Flying Poison, nothing was happening in the Drop of Wrath. Indeed, there was no remnant of Unclean Evil in the Drop of Wrath, only Axiu Qian's Flying Poison had endured. Thus, Cao Yun had to form it again. The Drop of Wrath was trying to repair itself. If he could give her a nudge in the right direction, it would naturally attempt to reform its Unclean Evil. But instead of Axiu Qian's Unclean Evil, it would be modeled after Cao Yun's.
Thanks to 'Death Verses', controlling his Po was easier for Cao Yun. Thus, he was able to take a small part of his Unclean Evil and sent it into the Drop of Wrath. Trapped in his Soul Nine Peaks, Cao Yun could feel the Flying Poison's excitement. This process took a while. But bit by bit, Cao Yun was both extracting his own Unclean Evil and reforming the one inside the Drop of Wrath.
Just as he was doing so, he could feel Dian Mo who was slowly eradicating all traces of Demon King Mo Wang. But even then, he was in some kind of deep sleep. No matter how much Cao Yun tried to talk with Dian Mo, he was unresponsive. After all, that operation was very critical and Dian Mo could very well damage himself beyond repair.
The third layer of Cao Yun's mind cultivation, 'Subdue the Seven Demons', would take around a decade to be done. Each step would most likely take between one to two years. In his current emotional state though, Cao Yun could easily cultivate his shame. In fact, he simply had to think about what he was letting happen around him. Just by overhearing the slaves and what the slavers were doing to them, he got more and more ashamed. At the same time though, his anger was getting stronger. As a consequence, his Flying Poison and his Drop of Wrath were also getting stronger.
On the other hand, it became more difficult for him to accept this situation. To be honest, Cao Yun was even on the verge of developing an inner demon. If he had to accept such injustice and cruelty in order to reach his goal, maybe he didn't deserve to do so. Maybe his sister was better off never seeing him again. Cao Yun could also imagine his family watching him from the Heavenly Court before being reincarnated. Not only was he ashamed of himself, he might also be shaming his family.
For centuries, Emperor Weide had used the demonic cultivators to perform experiments. All this time, Cao Yun was certain that he had claimed to have clean hands. After all, he wasn't directly doing anything. He had just been allowing the demonic cultivators and Demon King Mo Wang to do their thing. How was it any different from what Cao Yun was doing right now? If he could stay idle by while such cruelty was staring him in the face, how low would he stoop? Would he go to the extent of performing demonic arts in order to save his sister?
While those thoughts accumulated, Cao Yun slowly planned for the death of the slavers and the liberation of the slaves. As usual, the most important factor was to gather enough information. Since he couldn't get too much out of the slavers without exposing himself, Cao Yun might be able to get something out of the slaves. Even now, his caravan was close to the one where the women were being held. Thus, he might be able to use his spiritual senses to send his voice in there. He had trained with Xiao Xuefeng and could project his voice in someone else's mind. But then, he had to find the right candidate.
If the slave he contacted were to alert the slavers, everything could be ruined. As such, Cao Yun used everything he had learned about the slaves before choosing the candidate. Among the women, there was a young woman named Xixue. The other women seemed to look up to her. Although her cultivation was mediocre as she was in her twenties and was not even a 4th-grade Blood Child, she seemed to have a very strong will. No matter what the slavers had done to her, she had always endured stoically. The young man could tell she was the best candidate.