It took a full day for Lei Dong to finally refine all one hundred-plus wild ghosts and over two hundred wandering souls into the Myriad Ghost Banner. He then integrated his own concepts with traditional classifications for ghost generals, establishing distinct tiers for the different levels of vengeful spirits to avoid confusion. The specters refined from the most common Yin Souls and low-grade ghosts, Lei Dong dubbed 'Soul Worms.' They relied on sheer, dense numbers for victory, much like insects, and were equally fragile. In every battle, they served as cannon fodder, suffering massive casualties, yet remaining indispensable. Currently, their number within the Myriad Ghost Banner exceeded four hundred.

Those specters refined from ghost soldiers, Lei Dong named 'Soul Soldiers,' signifying they were on par with ghost soldiers. Naturally, the combat strength of a Soul Soldier was significantly different from that of a Natal Ghost Soldier, yet they were far superior to the Soul Worms. Originally, their numbers in the Myriad Ghost Banner were not substantial, but now, their total count had reached over one hundred.

Finally, the fierce and powerful vengeful spirits refined from Ghost Guards, or Foundation Establishment stage living souls, were designated 'Soul Guards' by Lei Dong, the name also drawn from the Ghost Guards. Individually, their combat prowess was far inferior to that of the Natal Ghost Guards. However, a mere contingent of these Soul Guards, despite their modest individual strength, became an absolute nightmare for any enemy once they achieved numerical superiority.

Regrettably, even with his current powerful divine sense, Lei Dong's control was still insufficient to pursue a purely elite strategy. If the Myriad Ghost Banner held several hundred Soul Guards, Lei Dong was certain that Tao Tai Bingyun and himself could ensure that any single opponent would be utterly devoured within ten breaths. Of course, given Lei Dong’s current cultivation, such a feat was beyond imagination, existing only as a fleeting fantasy. To recklessly absorb Ghost Guards into the Myriad Ghost Banner without restraint would only invite the backlash of the vengeful spirits, leading to his death.

These current five hundred-plus vengeful spirits represented Lei Dong's absolute limit. Although the total number was significantly lower than before, the overall destructive power had more than doubled. By now, this Myriad Ghost Banner was likely the most formidable magical artifact he possessed.

Having completed all this, Lei Dong hurried toward the exterior of the Black Demon Tower in his domain. Qi Feifei, clad in her Inspector's Cloak, was waiting there and gracefully appeared: "Senior Brother Lei, Feifei has already checked. This Black Demon Tower has not been breached, nor has anyone emerged from it."

"Let's go; we need to hurry. We are likely to encounter opponents in the next zones," Lei Dong’s voice was somewhat grave. He had spent the time maximizing the vengeful spirits in the Myriad Ghost Banner precisely because he knew the path ahead would be treacherous. He could only inwardly regret that he hadn't encountered any enemies in the region where his fighting strength was at its peak.

The two fought their way upward together. After jointly breaking through the tower, their luck was ordinary; they found no trace of the Heart Cleansing Fruit.

Next, the pair pressed through two more zones, still without obtaining the Heart Cleansing Fruit. It wasn't until the fifteenth zone that Qi Feifei suddenly sensed that Li Huntian of the Demon Prison Sect was nearby. Regarding a character as formidable as Li Huntian, Lei Dong initially preferred to avoid unnecessary conflict. Unexpectedly, Li Huntian had located the Black Demon Tower a step ahead of them.

This was already the fifteenth zone out of a total of one hundred and eight. Distributing them evenly meant each person received just over ten. The Heart Demon Palace trial was nearing its end. Lei Dong could not guess how many zones remained, but he was unwilling to risk it, especially since they still lacked one Heart Cleansing Fruit.

With this thought, Lei Dong had no choice but to directly confront that prodigious talent from the Demon Prison Sect.

Half an hour later.

In the grand hall of the first floor, Li Huntian expressionlessly collected his spoils and stored them away. Then, with hands clasped behind his back, he looked coldly at Lei Dong, his voice hoarse: "Lei Dong, out of respect for the Yin Sha Sect, I will not press the matter this time. If you speak such nonsense again about yielding this tower to you, don't blame me, Li, for disregarding our fraternal sect ties."

Lei Dong remained silent, summoning three peak Third-Tier Ghost Guards and arraying them before himself. Following that, he summoned the Soul Devouring Shadow Tiger, along with the hundreds of vengeful spirits from the Myriad Ghost Banner—especially the numerous Soul Guards and Soul Soldiers, all appearing massive, ferocious, and terrifying, baring their fangs at Li Huntian.

Initially, Li Huntian hadn't taken Lei Dong seriously. Among the younger generation of the Yin Sha Sect, the only ones he respected and paid heed to were the Yin Sha Twins. Seeing Lei Dong summon Ghost Guards, he didn't stop him, assuming he could muster at most two First or Second-Tier Ghost Guards. Who knew that the result would quickly send his heart racing—three Third-Tier Ghost Guards! Moreover, his Myriad Ghost Banner seemed exceptionally unusual, instantly causing Li Huntian's expression to darken, his voice grating like tearing metal: "Lei Dong, I admit I underestimated you. But do you think these alone are enough to defeat me?"

"Brother Li, please remain calm." Lei Dong narrowed his eyes and smiled: "Our two sects are not only old acquaintances but also strategic allies. My intention was never to clash with Brother Li. Who knows, we might have opportunities to cooperate in the future; causing trouble is pointless."

Li Huntian's stern expression softened slightly. Merely based on these Ghost Guards and that Myriad Ghost Banner, he no longer dared to look down on Lei Dong in the slightest; his gaze toward him was one of equal standing. Yet, caution remained: "Then, Lei Dong, what exactly is your intention?"

"I merely wish to engage in a fair trade with Brother Li." Lei Dong's demeanor was relaxed as he produced two Seeds of the Purgatory Red Lotus, levitating them in his palm. They shimmered with a brilliant red light, emitting an almost unbearable heat.

Almost instantaneously, Li Huntian's aura surged violently, and the flames in his eyes ignited fiercely as he roared: "Purgatory Red Lotus!?"

Seeing his reaction, Lei Dong sensed an opportunity and chuckled lightly: "If Brother Li already possesses two Heart Cleansing Fruits, please spare one for me, and these two Seeds of the Purgatory Red Lotus will belong to Brother Li."

"Where are the remaining seeds?" Li Huntian's face darkened menacingly as he said harshly: "One Purgatory Red Lotus plant cannot possibly yield only two seeds."

Lei Dong's smile faltered, a flash of malice crossing his features: "Li Huntian, you are being too greedy. Don't mistake courtesy for weakness." Netherworld ghost energy erupted around him, dense black mist swirling, occasionally materializing into a snarling, clawing fiend.

Li Huntian let out a strange, chilling laugh, a murderous intent flashing in his eyes: "Lei Dong, to exchange two Purgatory Red Lotus Seeds for one Heart Cleansing Fruit is too little. At least ten seeds." It was difficult to blame Li Huntian for losing control; the Purgatory Red Lotus held little use for Lei Dong—at most, it was a valuable heavenly treasure. However, for a cultivator like Li Huntian, who practiced the Great Heavenly Fire Technique, the Purgatory Red Lotus held a fatal temptation.

"Senior Brother Lei, your little sister also has two seeds here. Adding Senior Brother Lei's two, how about trading for one Heart Cleansing Fruit?" Qi Feifei, wearing the Inspector's Cloak and hidden about twenty feet away, manifested as she saw the two men's negotiation heating up, showing clear signs of being ready to fight. She revealed herself first to deter Li Huntian from any rash actions, and second because the Heart Cleansing Fruit was indeed important; exchanging four Purgatory Red Lotus Seeds for one was exceedingly fair. Li Huntian was startled by Qi Feifei's sudden appearance; she had closed the distance so much that he hadn't even noticed her. A look of shock flickered across his face before it settled into an uncertain gloom. This unfathomably profound Lei Dong had already shaken his confidence. Now, with Qi Feifei added to the equation, and seeing that she seemed to be allied with Lei Dong, if a fight broke out, facing two opponents might not yield any advantage.

Although he was arrogant by nature, arrogance alone could not sustain life in this world. At this moment, Li Huntian actually laughed, his tone shifting: "So it's Feifei. You've arrived at a good time. Help me reason with Brother Lei. Exchanging two Purgatory Red Lotus Seeds for one Heart Cleansing Fruit—that's clearly trying to cheat and extort."

Qi Feifei covered her mouth and smiled: "Senior Brother Li, Senior Brother Lei is being polite. For anyone else, he wouldn't offer even half a Red Lotus Seed. Who told you that you needed the Purgatory Red Lotus so badly? Furthermore, Senior Brother Li, you apprenticed under Martial Uncle Fen Wanli in the Demon Prison Sect; your backing is strong, your family prosperous. Why fret over a mere Heart Cleansing Fruit?" Qi Feifei also took the opportunity to remind Lei Dong that Li Huntian had powerful connections, and incurring his enmity would be pointless.

Li Huntian cursed inwardly; these two had indeed conspired together. He had to admit that the charming Qi Feifei possessed a certain allure, which was Lei Dong’s gain. He then burst into hearty laughter, his tone suddenly jovial: "Since Junior Sister Qi has put it that way, if I bargain further, it would lower my standing. Fine! Four seeds it is, then. No one loses, and we can get along better later. Moreover, we'll let you two have this Black Demon Tower to battle through." He was perceptive enough to know the wisdom of 'a wise man doesn't fight losing battles.'

"So Brother Li is Martial Uncle Fen's disciple..." Lei Dong said with a beaming smile: "Last time at Lord Heavenly Demon's Nascent Soul celebration, I had the honor of observing Martial Uncle Fen's might up close. I wonder how Emperor Yan is faring these days?" This information had actually been secretly whispered to him by the Heavenly Demon when Lei Dong expressed curiosity about what the Purgatory Demon Heart was. Now, using it to intimidate and suppress Li Huntian was both amusing and useful.

"You..." Li Huntian's face grew horrified, then shifted unpredictably. He thought frantically, How does this brat know that my Ancestral Master's health is failing? In truth, if the Ancestral Master hadn't suffered a qi deviation, consuming countless supreme demonic and yang treasures from the sect, someone of Li Huntian's status wouldn't have struggled to procure even a few Purgatory Red Lotus Seeds. It seemed this young man's background was far greater than he had imagined; he was not to be underestimated.