# Chapter 503: Great Secret
The calm blood pool suddenly let out a gurgling sound as a huge red bubble emerged from it.
The bubble burst, and with a whoosh, Zhang Ruochen flew out from inside.
Tree Ancestor had been guarding by the blood pool, already sensing the unusual movement in the pool and was on alert. Seeing Zhang Ruochen rush out from the blood water, it was somewhat surprised: "Outer Domain Death God, you weren't refined into blood water by the sacrificial power of the blood pool?"
Zhang Ruochen landed on the stone platform at the edge of the blood pool and smiled: "Sorry to disappoint you."
With that, Zhang Ruochen glanced toward the distant stone staircase entrance leading upward, took a step forward, stepped into the void, turned into a blurry afterimage, and rushed toward the stone staircase, preparing to leave.
"Outer Domain Death God, don't think of leaving."
How could Tree Ancestor let Zhang Ruochen go? It chased after him at an even faster speed, mobilizing wood-attribute spiritual energy and gathering it into its arms. That pair of wooden arms radiated boundless vitality and power.
Both palms struck out simultaneously.
Before the palm prints even landed on Zhang Ruochen's body, that powerful palm wind fluctuation surged forward first, striking his back.
Zhang Ruochen quickly turned around, mobilized the power of his spiritual force, and pushed both palms forward. Instantly, strands of heaven and earth spiritual energy transformed into threads of electric light, converging toward his palms.
All the electric light gathered together, forming two spheres half a meter in diameter.
"Boom!"
The two forces collided.
The massive altar shook violently, sending particles of dust falling.
The power of thunder and lightning scorched Tree Ancestor's pair of wooden arms black, emitting black smoke. Some parts even caught fire.
The ground and stone walls were covered with tiny lightning snakes, making a crackling sound.
When the black smoke dissipated, there was no trace of Zhang Ruochen.
"How infuriating! In such a short time, the Outer Domain Death God's power has increased so much."
Tree Ancestor, somewhat disheveled, gnashed its teeth and roared in anger. Then, it strode forward, stepping onto the stone staircase and chasing upward.
Although Tree Ancestor had suffered greatly in that exchange, Zhang Ruochen hadn't gained any advantage either. Even now, his arms were still aching as if they were about to split, completely unable to move.
"Tree Ancestor's cultivation has indeed reached the Fish-Dragon Fifth Transformation. Even if it's not skilled in combat, just its realm alone is a full level above mine."
Zhang Ruochen rushed upward while circulating true qi to heal the injuries in his arms.
Behind him, a powerful force fluctuation came. Without guessing, he knew it was Tree Ancestor chasing after him.
Zhang Ruochen immediately executed Space Displacement, teleporting seven times in succession, finally reaching the stone door at the top of the altar.
Opening the stone door from inside the altar was much easier and didn't require a sacrifice.
Zhang Ruochen pressed his palm into a depression on the stone door, injecting true qi into it. After a moment, the patterns on the stone door lit up.
With a bang, the stone door slid to both sides, opening a gap.
Zhang Ruochen took a step forward and rushed out of the stone door.
Outside the stone door, a loud shout rang out: "The Outer Domain Death God is out! Hurry, activate the formation and suppress him."
Below the altar, five Tree Kings and one hundred and eight millennium-old trees formed a circle, standing in different positions according to some mysterious pattern.
From each tree, a beam of light shot out, rushing toward the top of Zhang Ruochen's head, connecting together to form a huge light barrier.
Immediately, a powerful pressure, like an invisible mountain, fell upon Zhang Ruochen.
This Heavenly Wood Absolute God Formation was arranged by one hundred and eight millennium-old trees, each with strength comparable to a Fish-Dragon Realm cultivator.
Let alone Zhang Ruochen, even a Fish-Dragon Seventh Transformation powerhouse, once trapped in the formation, might not be able to escape.
"Outer Domain Death God, even if you have heaven-defying abilities, you won't escape today." A Tree King stood at the edge of the Heavenly Wood Absolute God Formation, laughing loudly.
No one noticed that on one branch of that Tree King, a mosquito-sized black cat was lying.
The black cat stood up and snorted coldly: "A mere insignificant tree dares to be so arrogant? This Emperor will teach you how to behave."
"Who's speaking?" That Tree King shouted sternly.
"Whoosh!"
Xiao Hei's body rapidly expanded, turning into a ten-zhang-tall giant beast. Its sharp claws swung out, instantly severing the Tree King's trunk.
The sharpness of Xiao Hei's claws was comparable to a sacred artifact.
Blood continuously gushed from the trunk.
After that Tree King fell, the originally invincible Heavenly Wood Absolute God Formation immediately had a gap.
The massive formation collapsed from the outside in.
Zhang Ruochen seized the opportunity, immediately circulating true qi and injecting it into the Lock Dragon Chain on his wrist.
This was a sacred artifact. True qi provided it with energy, activating layer after layer of inscription patterns. It spun around his wrist, turning into a water-barrel-thick giant iron chain, flying out like a steel furious dragon.
"Clank, clank!"
The Lock Dragon Chain wrapped around the trunk of one millennium-old tree. As Zhang Ruochen's arm exerted force and swung, an immense power erupted, directly pulling that millennium-old tree out from the ground and flinging it away.
A millennium-old tree's roots were at least dozens of meters deep, some even reaching hundreds of meters underground. Yet the Lock Dragon Chain had forcibly pulled it out. This showed the immense power of that strike.
With Zhang Ruochen and Xiao Hei joining forces, coordinating from inside and outside, they quickly knocked down a large area of trees, tearing the gap in the Heavenly Wood Absolute God Formation even wider.
Having already taken the source energy of the Wood Essence Ruins Realm, Zhang Ruochen had no intention of lingering. He fully circulated his true qi, charging it through the meridians in his legs.
"Bang!"
His body, like a cannonball, shot up from the top of the altar, flying several hundred meters away and landing on Xiao Hei's back.
"Let's go!"
Zhang Ruochen said.
Xiao Hei's wings on its back spread out with a whoosh, reaching twenty zhang in length.
With a single flap of its wings, a powerful wind force formed, blowing all the surrounding trees away. Even the trees in the distance were blown askew, their leaves stripped off and flying wildly in the air.
"Where do you think you're going?"
Tree Ancestor rushed out from the stone door, its eyes fixed on Zhang Ruochen on Xiao Hei's back, burning with green flames. It extended its arm, which turned into a several-thousand-meter-long wooden vine, spinning continuously as it wrapped around Xiao Hei's neck.
Zhang Ruochen swung the Lock Dragon Chain, colliding with that wooden vine.
An iron chain and a wooden vine, like two flood dragons and pythons, fought in midair.
After dozens of collisions, Zhang Ruochen and Xiao Hei finally managed to break free, escaping the encirclement of the tree clan.
Xiao Hei's speed was extremely fast. In moments, it left that towering altar far behind. Even Tree Ancestor, with its cultivation, couldn't match it in speed.
"Zhang Ruochen, why did you stay in the altar for so long before coming out? I thought Tree Ancestor had already killed you!" Xiao Hei said while flying.
Zhang Ruochen retracted the Lock Dragon Chain, which transformed back into a bracelet wrapped around his wrist. His expression was grave: "How long was I in the altar?"
"Almost ten days, I'd say. If you hadn't come out today, I would have definitely gone in to find you."
Xiao Hei paused, then continued: "Based on my research, that altar is really problematic. It was built no more than six hundred years ago, and it was definitely not built by the tree clan. It was constructed by human cultivators."
"The inscription patterns on the altar are extremely complex. At the very least, a human with spiritual power reaching the fiftieth rank would be needed to carve them."
Zhang Ruochen was shocked: "Spiritual power at the fiftieth rank? That means their spiritual power has already reached sainthood? How could such a figure come to the Wood Essence Ruins Realm to build an altar?"
A spiritual power saint's methods were even more unpredictable and harder to guard against than those of a martial saint.
Such an existence, each with vast divine abilities, was worshipped and revered by martial artists across the world.
How could they come to a lower-rank ruins realm?
Xiao Hei continued: "Moreover, I discovered that the altar seems to have a faint connection with certain distant coordinates outside the realm."
Zhang Ruochen was also intelligent and understood immediately.
His expression became extremely serious, feeling that he had discovered some earth-shattering secret: "You mean, this altar is just one of many. In other ruins realms, there are identical altars."
Xiao Hei nodded: "If you consider one altar as the foundation of a formation, then the altar deep in the Black Wood Plain is just one piece of the foundation. In the vast void, other ruins realms also have such altars built. All the altars connected together form a massive formation, probably capable of enveloping most of the Kunlun Realm."
Zhang Ruochen shook his head: "It's not just a single altar. If I'm not mistaken, the entire Wood Essence Ruins Realm is itself just one piece of that formation's foundation."
"Oh? What secret did you discover inside the altar?" Xiao Hei asked.
Zhang Ruochen said: "The source energy of the Wood Essence Ruins Realm is suppressed beneath the altar. Even those trees probably don't know this secret."
Once the altar was activated, it could extract the source energy, providing energy for the altar.
Extracting the source energy was essentially extracting the spiritual energy of the entire Wood Essence Ruins Realm.
That was why Zhang Ruochen said the entire Wood Essence Ruins Realm was just one piece of that formation's foundation.
Xiao Hei laughed loudly: "Such a massive project is rare even in human history. I wonder who is controlling everything behind the scenes, even more ambitious than this Emperor. Not simple, not simple at all! Haha!"
Zhang Ruochen snorted coldly: "Besides the central court of the First Central Empire, who else could do it? What exactly is Chi Yao trying to do? Does she intend to refine the entire Kunlun Realm and all the myriad ruins realms?"
Zhang Ruochen even suspected that the reason the Wood Essence Ruins Realm prohibited martial artists above the Fish-Dragon Realm from entering was precisely to prevent anyone from discovering the secret here.
Even if a Heavenly Extreme Realm martial artist came to the Wood Essence Ruins Realm, they couldn't venture deep into the Black Wood Plain. Moreover, with the knowledge of a Heavenly Extreme Realm martial artist, even if they saw the altar, they wouldn't know its purpose.
Hearing Zhang Ruochen's words, Xiao Hei laughed instead: "It's not necessarily Empress Chi Yao controlling everything. It could be some high-ranking official in the Ministry of War of the imperial court, setting up a scheme on the ruins realm battlefield. Why are you so certain it's her? Isn't that a bit too biased?"