Su Yi didn't know whether the poison of Devil's Death Grass could kill the dog-headed monster.

But based on his understanding of the poisonous nature of Devil's Death, even if the poison could not kill the dog-headed monster, it would still be enough for the dog-headed monster to drink a potful of it.

With this ghost dead grass to contain the dog-headed monster, Su Yi is confident that he can successfully obtain the fourth level of ancient body refining skills.

Su Yi slowly flew upwards. He didn't stop flying until he was close to the dog-headed monster that could find him.

He found a big stone and began to sit cross-legged and practice silently.

Several months passed before I knew it.

On this day, it seems that it is time to eat again.

The dog-headed monster flew downwards very excitedly.

Su Yi did not dare to delay. Soon after the dog-headed monster flew down, it flew straight into the stone cave engraved with the fourth level of ancient body refining techniques.

Resisting the lingering body odor of the dog-headed monster in the cave, Su Yi sat cross-legged and began to feel the fourth level of ancient body refining techniques with his heart.

The fourth level of old physical refining techniques is more complicated and more powerful.

After a moment, like the stone carvings in the other three caves, faint light spots flew into Su Yi's mind.

The fourth level of ancient body refining techniques was instantly imprinted in his mind.

The moment the imprint of the ancient body refining technique was completed, Su Yi opened his eyes with joy on his face: "I finally obtained the fourth level of the ancient body refining technique."

"Then I would like to congratulate you!"

An old voice came from behind, making Su Yi almost jump in fright.

I saw an old man with a faint light all over his body. He didn't know when he appeared at the entrance of the cave, blocking Su Yi's way.

The old man's body seemed to be translucent and looked quite strange.

Su Yi did not dare to carelessly pat the storage bag and took out a large number of talismans.

"What are these children's toys for?"

The old man chuckled, then waved his sleeves and picked up Su Yi like a little chicken.

Su Yi was horrified to find that facing this old man, he had no room for resistance.

The old man took Su Yi and flew down.

Because Su Yi was suppressed by the old man and couldn't move, he couldn't eat the wind grass, so he could only let the biting wind blow on him.

He was brought to the huge iron gate by the old man.

There, the dog-headed monster lay motionless on the stone slab, apparently dead.

The old man looked at the iron gate as if it were nothing and walked through it easily.

But halfway through, he stopped suddenly, as if he remembered something, and glanced at Su Yi.

Su Yi was so cold that he almost fainted from the cold.

A thin layer of ice formed around him, and his whole body was close to freezing into a popsicle.

"It's hard to get through horizontally, but it's just right vertically."

The old man positioned Su Yi's body parallel to the iron railings of the iron gate, just in time to bring Su Yi over.

The old man held Su Yifei for a while and threw him to the door of a prison. Then a booklet and a writing brush appeared out of thin air in his hands.

"Kill the guardian monster and be sentenced to three hundred years in prison."

"Studying the forbidden law secretly will be sentenced to five hundred years in prison."

I could only hear the slight friction sound of the brush writing on the booklet.

After the old man sentenced Su Yi, he took out the key from his waist, opened the prison door, and threw Su Yi in.

Then there was a click, and the old man locked the prison door again.

Su Yi was passive and unable to move.

Fortunately, when his body hit the ground, it shattered the ice that was frozen on his body.

He reluctantly sat up, closed his eyes, and began to run his exercises, hoping to resist the severe cold.

But Su Yi was shocked to find that the spiritual power in his body seemed to disappear out of thin air. No matter how he used his skills, he could not feel a trace of spiritual power.

Not only that, the ghostly spirit in his body was also gone.

This made Su Yi extremely scared. If this continues, he might freeze to death here.

"Hey, don't waste your efforts. After entering this hell, do you still want to use your spiritual power?"

A faint voice came from the darkness of the prison. Su Yi didn't know whether the voice was a human or a ghost, but he was unable to move at this time. Even if the person who spoke was hostile to him, there was nothing he could do.

"I just heard from the cell leader that you secretly learned the forbidden technique? It stands to reason that if you practice the forbidden technique at the fourth level, you won't be frozen to death by the evil wind. Judging from your appearance, you may be frozen to death by the evil wind?"

This faint voice woke up Su Yi.

Although Su Yi cannot summon spiritual power or the power of the netherworld, his body's instincts still exist.

He began to close his eyes and silently practice the first level of ancient body refining techniques.

Due to his foundation in body refining, and the fact that Su Yi's body itself has a strength that exceeds the Great Perfection state of the late human Nascent Soul.

This first level of ancient body refining technique only took a mere month to master.

After mastering the first level of ancient body refining techniques, the chill in Su Yi's body was reduced by three points.

Su Yi continued his efforts and prepared to practice the second level of ancient body refining techniques.

It took a full ten years to master the second level of ancient body refining techniques.

After practicing the second level of ancient body refining techniques, Su Yi was able to move a little.

The owner of that faint voice seemed to be very patient and did not interfere with Su Yi during Su Yi's practice.

Instead, he would give some advice on Su Yi's cultivation from time to time.

Su Yi ignored this person's advice. After his body could move, he began to practice the third level of ancient body refining techniques.

This practice lasted thirty years.

After mastering the third level of ancient body refining techniques, most of the chill in Su Yi's body had disappeared.

Since it was estimated that the fourth level of ancient body refining techniques would take at least a hundred years of practice to master, Su Yi was ready to meet the owner of this voice.

It was pitch dark inside the prison, and it was unknown what material the prison was made of. The people locked inside were not only unable to use spiritual power, the power of the netherworld, but even their spiritual consciousness was affected.

Su Yi slowly said: "Who are you, your Excellency, and where is this place?"

The man chuckled and said, "Little baby, didn't we tell you from the beginning? This is heaven."

Su Yike had never heard of the Heavenly Prison, so he asked: "What exactly is the Heavenly Prison, and the previous prison chief? Why was Su Mou killed after just killing a dog-headed monster?"

Sentenced to imprisonment for three hundred years."

"Also, many elders in the Vajra Sect have practiced the ancient body-training method. Why not capture them and lock them up?"

The man smiled again and said: "The so-called dog-headed monster you killed is a guardian monster. It is not easy to cultivate one. It is fair to sentence you to three hundred years."

"As for the Vajra Gate you are talking about, I don't know much about it, but there is no harm in practicing the first three levels of the forbidden method. But if you practice the later forbidden methods, you will be imprisoned for five hundred years. You deserve it. Have you ever seen the first three levels?

Is there a guardian beast guarding the forbidden law?"

Su Yi was startled when he heard this, then shook his head and said, "Indeed not."

"Su has another question, who are you? Are you also imprisoned here because of the ancient body-refining techniques you practice?"

The man sighed: "I am also imprisoned here because I deserve my crime."

After saying that, he sighed again and again, as if he regretted the crime he had committed.

When Su Yi tried to communicate with the person next, the person didn't say a word and began to become silent.

Su Yi had no choice but to continue practicing the fourth level of ancient body refining techniques.

...

The cultivation of this fourth level of ancient body refining skills is much more difficult than the previous levels. Su Yi went astray several times and almost went crazy.

Fortunately, at the critical moment of practice, that person always spoke up to give advice, and Su Yi was able to complete the fourth level of the ancient body refining technique.

This ancient body refining technique is quite magical.

There is no need for the assistance of elixirs or magic weapons. After practicing, your whole body will be full of strength.

Su Yi punched the cell door.

Boom, a muffled sound came out.

Su Yi's fist actually sparked sparks with the cell door, which was made of an unknown material.

After Su Yi's body cultivated into the fourth level of ancient body refining techniques, his body's strength reached an incredible level.

At the moment when Su Yi's fist made sparks with the cell door, Su Yi saw clearly the face of the man who had been encouraging him to practice.

This person is from a human race, which is not beyond Su Yi's expectation.

What surprised him was that the man's whole body was penetrated by iron chains, and his entire old body was riddled with holes, making him look miserable.

At the wound where the iron chain penetrated, the muscles and the iron chain had grown together. It seemed that the iron chain had penetrated the man's body for a long time.

Su Yi unknowingly had been practicing in this prison for more than a hundred years.
Chapter completed!