"Heugh," Zac retched as he spat the lake water onto the ground, and he helplessly watched it seep into the soil.

After the success of eating the Dao Crystals, it had seemed like a solid plan to simply drink the lake water, preventing any of its mysterious insights from slipping away. One mouthful, one insight - easy enough. But who would have thought his body would reject it so vehemently? He didn't even get a taste of the truths of the Lost Plane before a huge sense of disgust overwhelmed everything.

Had the water spoiled inside the canisters? No, it didn't smell any worse than before, and it was still mostly clear. The corruption of the Lost Plane didn't seem to taste anything, either. Was it a mental block, or was his body protecting him from doing something stupid? Either case, it wasn't the end of the world. The first method had failed, but there were many more.

Zac took out a large bowl and filled it with lake water, and a surprising scene immediately occurred. As soon as it left the canister, the water started releasing plumes of vapor even though it was room temperature. In other words, it wouldn't last long outside its containers. Zac guessed it had something to do with the fact the water was no longer connected to the Lost Plane through the spatial tunnel. It had become rootless, like a harvested Spiritual Plant.

There was no time to waste, so Zac quickly dunked his head into the bowl. Almost immediately, he felt the corruption seep into his head. This was just a test where he wanted to check whether he could directly gain insights from the corruption before his Hidden Nodes refined it, leaving more insights for himself and less for [Void Heart].

Unfortunately, this experiment was a failure as well. The only thing Zac gained were distant voices clamoring in the back of his mind until the corruption was dragged down to his heart for purification. Not only that, but the small amount of taint absorbed by just dunking his head allowed [Purity of the Void] to destroy a significant portion before it could enter [Void Heart].

A moment later, the purified comprehension was released from the Hidden Node in his heart, and Zac was provided a flash of clarity. But again, with the amount being so little, he didn't manage to take even a step forward with his comprehension of Duality before the moment passed. It looked like it was time to get back to basics, so Zac took out a large medicinal bath and filled it with lake water.

With water reaching his chin, Zac was soon filled with corruption, and more kept pouring in. He even started to feel his perception shift, but [Void Heart] was already fast at work refining the water into something usable. Soon, his Soul Aperture was filled with the light of truth, and Zac was methodically deciphering one character after another from the [Book of Duality].

Ten minutes later, the corruption had either been absorbed, purified, or dissipated into the air, leaving only common water behind. Zac took a deep breath as he thoroughly scanned his body. Thankfully, no matter how hard he looked, it seemed there weren't any negative side effects from this type of cultivation.

The corruption wasn't a tangible element, so there were no physical impurities that could hamper his cultivation. It was more akin to a Dao-infused wound, but his bloodline was uniquely capable at dealing with things like that. Neither did interacting with the corruption seem to impact his still-damaged foundations. More things might crop up after prolonged use, but it really seemed as though the lake water was suitable for long-term cultivation.

Of course, he hadn't forgotten the lessons he'd learned while trapped in the poisonous sea. Vai's research notes had shown how small alterations to his approach could have huge benefits. A few percent improved efficiency here and there would accumulate just like his Titles, and a perfected cultivation method might be twice as good as simply sitting down in the water.

Like this, days passed as Zac entered a cycle of cultivation, comprehension, and experimentation.

Zac's most important goal was to waste as little lake water as possible. He did have a huge amount of it stored in his canteens, but it was still a finite resource. The first step was to find the right quantity of water per session. Zac soon realized that the amount of water used had a noticeable effect on how much corruption he absorbed per second. In other words, it was not just a matter of covering all of his body.

It was just like when he visited the lake itself. Back then, just a few seconds was enough to overload him if he didn't use [Void Zone] as a buffer. The absorption rate was far lower when using the water in a tub. However, when Zac changed his smaller tub for a larger medicinal bath, the rate increased for some reason.

The key was to find a level of optimal efficiency. Too little water, and [Purity of the Void] would purify and waste a large chunk of it. It was an annoying reminder that his Bloodline Method [Bloodline Resonance] was just utter garbage, completely incapable of providing Zac with even a semblance of control over most of his bloodline.

Conversely, if he used too large a vat and too much lake water, he would instead lose a large amount of it to the atmosphere, and he had found no way to salvage the insights by that point. Eventually, Zac figured out the right balance by constructing a larger bath of two-by-two meters and filling it up to his chest when sitting.

By that point, Zac started another series of experiments to improve the process even further. Unfortunately, the type of arrays that medicinal baths used to retain medicinal energy were completely incapable of trapping the corruption. Heating the water was even worse – it rapidly increased the dissipation rate.

Conversely, cooling the water had the opposite effect, so Zac had Triv install Ice Arrays that lowered the temperature far beyond what could be found in nature. Allowing the water to turn into ice would ruin the absorption process, but Zac circumvented that by adding powerful Gravity Arrays. Working in conjunction, Zac pushed the lake water far into sub-zero degrees, drastically improving the retention.

The gravity arrays even helped stimulate his bloodline a bit, allowing him to absorb the corruption faster. That way, he could add more water per session without any downside, further speeding up his cultivation. The catch was that the sessions grew a lot more grueling. Between the blistering cold and crushing pressure, most F-grade cultivators would instantly die after entering the vat.

Even then, Zac mostly felt nostalgic as he silently endured the torture. It made him think of his first weeks on Demon Island, when he was still finding his way in this new reality. A Gravity Array had been one of his first purchases from the town shop, and it had allowed him to refine his body and gain a few attribute points.

Today, he endured a punishment hundreds of times more severe, but Zac was certain he wouldn't gain any attributes even if he spent years in these arrays. He had all but exhausted the untapped potential in his body. Common E-grade warriors might be able to gain a few hundred Attribute Points through decades of painstaking work. But elites who had elevated their bodies through Daos, Attribute Fruits, and Titles had very little room for conventional gains.

Another discovery was that he couldn't just keep absorbing the water indefinitely. After roughly an hour of cycling water and epiphanies, his mind was completely shot, like he had been cramming for an exam for 24 hours straight. Even if his [Void Heart] kept extracting the marvelous insights, it barely allowed him to digest any more knowledge.

Perhaps it was for the best. Forcibly pushing his understanding forward at a breakneck pace might lead to rickety foundations. It was better to take things one step at a time and digest what he'd learned after every session.

And it wasn't like Zac didn't have other things to do. Ten days after secluding himself, he resumed his Soul Cultivation, which took up most of his time. Zac had initially planned on waiting a bit longer, but he had no choice. The Moss Crystal was continuously feeding him, but the energy it released wouldn't just perfectly meld with his Soul Cores on its own. If he didn't start refining the energy, he'd end up weakening his cores.

That could be considered the real downside of the Moss Crystal. Zac estimated he would start running into trouble if he didn't run his method at least twice a week on average. Any less and his soul would eventually be riddled with imperfections.

If this had happened while in the Twilight Ascent or the Void Star, such a situation might have spelled trouble; he didn't have the luxury to set aside whole days for soul cultivation back then. Luckily, he was back on Earth now, and the downside was no downside under these conditions.

Another piece of good news was that running his [Nine Reincarnations Manual] extracted even more energy from the Moss Crystal, speeding up his cultivation speed even further. At this pace, Zac believed he'd finish forming his next set of outer cores in a few months, saving him potentially years of effort.

Then finally, the day came. A full three weeks had passed since returning from Emerald Eye, and Zac judged his body was finally in condition to try out the grand prize from his visit to the Void Star – the [Void Vajra Sublimation]. Between the healing baths and top-tier environment, Zac had recovered a bit earlier than expected.

Over the past week, he had gone over his new method numerous times just to ensure there weren't any mishaps. Though honestly, he wasn't sure it was needed. The old [Boundless Vajra Sublimation] had somehow been engraved onto his mind by Three Virtues, with every single detail as clear as day. Later, the seal of the Left Imperial Palace had reforged that parcel of imparted memories, which would have allowed him to start cultivating back in the Void Star already.

The only reason he hadn't done so was that he had too much on his plate, and the lingering worry of there still being traps hidden in the depths of the method. But no matter how he looked, the dangerous elements were solved by completely swapping out the Heart Cultivation aspect of the Body Tempering Manual. Even the movements and medicinal array patterns had been altered to suit his new direction, leaving none of the three pillars of the method entirely intact.

Zac wasted no time as he walked over to a grove inside the life-attuned side of his cultivation Cave. In the beginning, the environment had mostly been powered by the [Lotus of Harmony], the [Primordial Breath Amanita], and Divine Crystals. Similarly, the Miasmic side utilized the odd seed the Undead Empire used as an array core to realign planets along with Miasma Crystals.

But the Nexus Veins beneath the island had gradually transformed as Earth continued its transition into a Life-Death world. Most of the veins were still unattuned, but both Divine Veins and Miasmic Veins had started to crop up here and there. Now, two of the purest veins were the main source of attunement in his cultivation cave, providing the environment with nigh-endless energy of Life and Death.

Triv had already prepared a spot to practice his Body Tempering Manual, an undertaking that had led to no small amount of suffering for the poor ghost. The spectral butler had looked so wan after spending time inside the Life-attuned Forest that Zac had given him a vacation and a couple of Death-attuned treasures to recuperate.

Now, the small grove was already instilled with Gathering-, Purifying-, and Gravity arrays to maximize the efficiency of the Body Tempering Manual. He had made some inquiries into getting the Arhat Golden Flames mentioned in the manual, but he couldn't find anything like it in Zecia. Besides, Zac wasn't even sure the treasures mentioned in the old method would even work after he had reformed the [Void Vajra Sublimation].

This was the first time he cultivated the method, so Zac only activated the Purifying Array as he got completely naked. Here beneath the mountains, there was no point in covering himself. He had already burnt off his hair and beard to more easily tack on the medicinal mixture. One line after another of life-attuned paste was added across his body, and he was covered from head to toe in no time.

The new pattern was similar to the original arrays he had painted on himself while trapped in the Undrusian sea, yet different. It felt inverted somehow, even if the array was clearly a manifestation of Life. It reminded him of the difference between seeing himself in a mirror and a picture.

Zac couldn't quite remember or understand the underpinning concepts that led to these changes. Now that the boundless comprehension of Ultom was long gone, he was only left with vague and blurry impressions. He could only remember that the changes were done to allow for a greater harmonization between the materials and a Heart Cultivation centered on the concept of the Void, rather than the Buddhist harmonization with the cosmos.

All done, Zac started moving with pinpoint precision, following the new sets of movements designed to agitate his cells and allow them to accept the medicinal paste. Just like the array covering his body, the movements were both familiar and foreign. But with the experience he'd accumulated by this point, he easily completed the first cycle.

"Ka," Zac uttered, followed by a sharp inhalation the moment his right foot slammed into the ground.

It felt like the whole cave – the whole world – shuddered from the step, and Zac's perception immediately shifted.

When he had tried out the [Boundless Vajra Sublimation] in the Void Star, this step of the manual elicited a sense of profound vastness. It had felt like his body was being tuned into the frequency of the cosmos, connecting him with all of creation. That way, he was one with all, and for Life to meld with his body was natural and expected.

This time, the feeling was diametrically different. Instead of being one with the universe, Zac felt like he had stepped out of the Multiverse. He had become the all-encompassing Void, everything and nothing at once—a small island of nothingness surrounded by a sea of being.

His step had not opened or tuned his body to the Heavens - it had breached the impermeable layer between real and unreal. He could even see a hidden seal beneath his foot; an impossibly intricate spiral pattern reminding Zac of a black hole. It wasn't really there, yet it was. It was a manifestation of the heart—a heart attuned to the Void of Dao.

Something that might only be achievable by Zac across the whole Multiverse.

And through this mysterious breach, Life poured into the Void – into his body. There was no clash like when Life and Death struggled for supremacy inside his Cultivation Cave. The Void could accept anything, yet only Life poured into his body at the moment. The medicinal array, the steps, the breathing. They were designed to snatch Life while keeping the rest of the cosmos at bay.

Reality acceded to the undeniable truth in Zac's heart, and his body heated up as the energy was dragged into his body by the pull of the Void. The pain was agonizing, but Zac barely registered it. He had entered an ethereal state where everything was absorbed and consumed. The life-attuned paste and the ambient energy. The pain. Even his thoughts.

It all entered the black hole of his existence, becoming fuel for his path.

Another step, another seal, and another breach to welcome Life into the Void. Altogether, eighty-one aspects of the Void formed a complete circuit, both with the Dao of Life and within his body. Any more, and extraneous concepts would be allowed to join the perfect system. Any less and the transformation would be imperfect, incomplete.

So Zac preserved through the pain, moving toward the next expression of the Void. But it was at that point his perception was nudged, almost to the point Zac lost his focus. It was [Void Heart] which had finally woken up, and it greedily wanted to consume the foreign energies that had entered his body. It felt like the Void had splintered, with there suddenly being two black holes—himself and his Hidden node, both competing for the same energy.

Zac knew this would come, yet he couldn't help but feel a wave of annoyance upon sensing some of the energies, his energies, drift toward his heart. Going through the eighty-one aspects of the Void and completing a Body Tempering Session would take over an hour, and who knew how much energy [Void Heart] would manage to steal?

Even worse, with this kind of energy, it would only return bog-standard Cosmic Energy, completely wasting Zac's time. Losing some resources was fine, but losing months of progress was not. Zac kept going through the motions of the [Void Vajra Sublimation], not wanting to stop prematurely and waste a whole session.

But in his mind, Zac was roaring at [Void Heart] to stop, to give him a break.

And the node obeyed.