Suddenly, a burst of verdant energy materialized from within the immortal mist, darting like a fish through the immediate vicinity of the spring's core. "Void Secret Realm!" It had finally appeared!

Nie Kong let out a breath of profound relief. This "Void Secret Realm" resembled a slender-necked vase, scarcely half a foot long, exquisite and compact.

It had completely merged with the spring’s eye, its surface already saturated with a deep emerald hue. Otherwise, even if it had been lured out by the "Chaos Immortal Qi," it would have been nearly invisible to the naked eye.

On the surface of this vase-like "Void Secret Realm," a dense lattice of crisscrossing lines could faintly be discerned. These were the phantom shadows cast by the roots of the "Ancestral Heaven Divine Luo Tree" manifesting at the boundary of the secret realm.

This completely verified Mu Zu’s intuition: his roots had indeed, without his notice, permeated the spatial barrier of the "Void Secret Realm." "Hum!" The jade-green vessel trembled with an almost imperceptible vibration, and another ball of "Void Power," enveloped in green, was slowly expelled from the mouth of the vase. This was the sixth instance of Void Power Nie Kong had witnessed since entering the spring's eye.

With a flicker of thought, Nie Kong directed the energy—now as large as an infant's fist—to shift its trajectory under the compression of the "Chaos Immortal Qi," allowing it to settle gently into his palm. "It can begin now!" Mu Zu, who had been sitting silently nearby, suddenly opened his eyes.

His body dissolved into a green shadow and drilled directly into the mouth of the "Void Secret Realm." Immediately afterward, Nie Kong’s spiritual consciousness followed. The moment he entered the vase-mouth, the surrounding scenery underwent a dramatic transformation.

The heavens and earth were filled with an endless, milky-white aura, seemingly boundless. This was the spatial barrier of the "Void Secret Realm," the true gateway to its interior.

"Little fellow, the future rests entirely upon you." Mu Zu’s gentle voice had barely faded before his form melted into the spatial barrier. "Boom!" As if a massive stone had been dropped into a placid lake, the spatial barrier boiled violently, the mist-like aura beginning to churn fiercely.

Within the barrier, the long, thick roots of the "Ancestral Heaven Divine Luo Tree" became intermittently visible, resembling colossal flood dragons maneuvering and leaping through the clouds and fog. Soon, Nie Kong noticed these roots continuously swimming forward.

After a while, all the roots vanished into the distant white mist, followed by the immensely massive trunk of the "Ancestral Heaven Divine Luo Tree," which revealed itself within the spatial barrier. As time flowed, the bulk of the trunk slowly diminished in size, seemingly moving relentlessly toward the distance along with its roots.

Much later, the enormous branches finally appeared. Like images on a lantern slide, the branches flashed one after another before Nie Kong's spiritual perception.

Amidst the violent surge of the white mist, the branches and trunk alike continued to shrink. After an indeterminate passage of time, the very tip of the "Ancestral Heaven Divine Luo Tree" manifested.

Accompanying the treetop was a colossal root of the giant tree. The "Ancestral Heaven Divine Luo Tree" had effectively circled the entire perimeter of the "Void Secret Realm's" spatial barrier, connecting its head and tail.

The instant the longest root touched the treetop, time and space seemed to freeze abruptly. "Crack!" It felt both like the snap of a finger and the passage of ten million years; a sudden, faint fracturing sound caused the spatial barrier to erupt into renewed turmoil.

From root tip to treetop, a narrow, elongated fissure split open across the "Ancestral Heaven Divine Luo Tree." "Whoosh!" Immediately following, an infinite expanse of emerald vitality—like a flood breaking its banks or a ferocious beast escaping its cage—roared out from the rift. This green energy contained a terrifying degree of life force; as soon as it appeared, it spread rapidly in all directions, intermingling with the spatial barrier.

As the green energy intensified, the previously turbulent spatial barrier gradually calmed until the entire expanse became a uniform, brilliant green. Yet, the form of the "Ancestral Heaven Divine Luo Tree" remained distinct.

At this point, its root section had completely integrated into the spatial barrier, but the treetop seemed somewhat incongruous with its surroundings. "Not good!" Nie Kong's heart lurched.

Although he was only observing the state of the roots and the crown, he could deduce the overall situation. Mu Zu possessed the power of a Tai Zun, but he was ultimately not a true Tai Zun, whereas this "Void Secret Realm" was an independent space condensed by the "Primordial Chaos Immortal Spirit" upon reaching the Tai Yi Realm.

This vast disparity in cultivation made Mu Zu’s integration into the spatial barrier exceedingly difficult. "I am not a Tai Zun after all; I am struggling somewhat," Mu Zu echoed this realization, his ancient, hollow sigh drifting from within the spatial barrier.

"Mu Zu, leave the rest to me." Nie Kong’s spiritual consciousness manifested as a phantom form, his expression grave as he declared this. Then, with a thought, the vast surge of "Chaos Immortal Qi" from the spring's eye poured through the "Void Secret Realm’s" mouth, inundating and adhering to the spatial barrier before spreading out in fine threads.

When that segment of "Chaos Immortal Qi," mirroring the "Ancestral Heaven Divine Luo Tree," circled the spatial barrier once and returned before Nie Kong, the several thousand meters of luminous white light instantly ascended, erupting into brilliant yet soft rays that bathed the spatial barrier. The next moment, that "Chaos Immortal Qi" ignited into a fire as white as snow.

In an instant, this "Great Sun Chaos True Fire" engulfed Mu Zu’s silhouette. While "Chaos Heavenly Fire" was optimal for refining power, "Great Sun Chaos True Fire" was necessary for fusing power—especially when fusing Mu Zu with this very "Void Secret Realm." The flames roared, swiftly spiraling along the spatial barrier.

Mirroring the refinement of the tenth-grade spiritual medicine, the "Serpent Dragon Entering God Pill," Nie Kong was employing his peak alchemical technique, "Ten Thousand Li Wind and Fire." In Nie Kong's eyes now, Mu Zu’s "Ancestral Heaven Divine Luo Tree" body and the "Void Secret Realm’s" spatial barrier were two medicinal ingredients. His task was to fuse these two components into one.

"Hoo!" Beginning with the roots of the "Ancestral Heaven Divine Luo Tree," this iteration of "Ten Thousand Li Wind and Fire" moved in reverse. Just as Nie Kong had surmised, the integration between the tree's first branch and the spatial barrier was incomplete.

Counting from the roots, Mu Zu had managed to fuse about half of the structure; Nie Kong only needed to focus his energy on the remaining portion. The Great Sun Chaos True Fire burned intensely; the heat emanating from the flames acted as the most divine catalyst, embedding Mu Zu’s essence further.

The unique aura of the "Ancestral Heaven Divine Luo Tree" gradually faded, while the aura of the spatial barrier grew steadily stronger. Mu Zu’s integration made the inherently fragile "Void Secret Realm" increasingly robust.

After a very long time, the Great Sun Chaos True Fire completed one full rotation around the spatial barrier. When refining the "Serpent Dragon Entering God Pill," one rotation only covered a meter, requiring at least five million revolutions to fully exert the effect of "Ten Thousand Li Wind and Fire." However, fusing Mu Zu and the spatial barrier required only a single rotation of the flames.

With a subtle mental command, the Great Sun Chaos True Fire extinguished, and the massive white sun instantly sank back into Nie Kong’s body. Now, within the emerald-green spatial barrier, only the faint shadow of the "Ancestral Heaven Divine Luo Tree" could be seen, as if its enormous body had become fossilized, appearing indistinct and shadowy.