After walking out of the corpse's prison, Gu Qingfeng couldn't wait to go to the next cell. With the system here, this place is simply a treasure trove for becoming stronger.

The Demon Suppression Prison is divided into three floors. The first floor is for low-level demons and evil spirits, the second floor is for middle-level demons, and the third floor is for high-level demons.

Gu Qingfeng is an apprentice exorcist and can only patrol on the first floor. He is not good enough at the second or third floor and cannot go there.

If you want to go to the second level, you need to be at least a Yellow-rank Demon Slayer, and only those above the Profound rank can go to the third level.

The officials in the Demon Suppression Department of the Great Yan Dynasty were called Demon Exorcists.

Demon slayers are divided into four levels: heaven, earth, black and yellow. Among them, the heavenly level demon slayers are the highest level and the strongest, while the yellow level demon slayers are the opposite.

Gu Qingfeng, the trainee demon hunter, is at the lowest level of the Demon Suppression Bureau, a non-staff member, equivalent to a temporary worker. Only after he is converted to a regular employee, can he be considered a yellow-level demon hunter and have a regular and official status.

Although he couldn't go to the second and third floors for the time being, there were many demons imprisoned on the first floor of the Demon Suppression Prison, which was enough for Gu Qingfeng to slowly travel around.

So Gu Qingfeng walked towards the next cell.

But at this moment, footsteps suddenly came from a distance, followed by a voice: "Gu Qingfeng, it's time to change shifts."

Grass (a kind of plant)!

Gu Qingfeng couldn't help but curse inwardly when he heard this voice. If it were normal times, he would be eager to hear this sentence, it was time to change shifts.

But now.

Which shift?

The Demon Suppression Prison is my home. I want to live here every day! I won't leave!

"Okay, I'm coming." Gu Qingfeng agreed helplessly, then turned and left.

He wanted to live here, but the rules of the Demon Suppression Bureau did not allow it.

If you force yourself to do so, people will definitely suspect that you have been bewitched by demons.

Gu Qingfeng clearly remembered that his system became stronger when attacked by monsters, not when being attacked.

The difference of two words can make a world of difference in meaning.

It seems that my future behavior can only be: in front of people, I am submissive and kind to others. But when facing demons, I will strike hard and be infinitely arrogant!

Soon, Gu Qingfeng and his colleagues switched shifts and walked out of the Demon Suppression Prison.

Only then did he realize that it was already daybreak. He realized that he had already stayed in the Demon Suppression Prison for a whole night without realizing it. As expected, happy times are always short-lived.

Under normal circumstances, Gu Qingfeng would have returned home and fallen asleep by now, but this night his defenses had been strengthened, causing Gu Qingfeng's physical condition to also improve, and he did not feel sleepy at all even after staying up all night.

So Gu Qingfeng went straight to the Sutra Library of the Demon Suppression Bureau. He wanted to verify an idea.

Gu Qingfeng jogged all the way and soon arrived at the Sutra Repository. It was early morning and there was almost no one in the Sutra Repository.

Gu Qingfeng took out his identity token, verified his identity, and went straight to the first floor of the Sutra Library.

Currently, as an apprentice demon slayer, Gu Qingfeng can only enter the first level.

The first level contains some low-level skills, some demon illustrations, and miscellaneous records of unofficial history.

After entering, what catches your eye are rows of dazzling bookshelves.

Fortunately, Gu Qingfeng had been to the Sutra Repository several times and was quite familiar with it.

He came to the external skills area and began to search according to the catalog.

After a stick of incense, Gu Qingfeng had a book in his hand, on which were written three big characters: "Iron Shirt".

The Iron Shirt martial art is very popular. Almost all major forces in the martial arts world have included it. Both famous and small sects have copies.

The reason why it is so widely spread is that Iron Shirt is a very simple horizontal training martial art that has no requirements for qualifications. Anyone can practice it and it is easy to get started.

But those who really have the conditions will not choose to practice Iron Shirt.

Because it is a hard skill. Although it is easy to get started, there is absolutely no shortcut to master it. You can only rely on hard work. Without more than ten years of hard work, it is impossible to achieve great success.

The cost-effectiveness is extremely low, so most people are unwilling to refine it. At most, they learn from the above methods to strengthen their bodies.

Then why did Gu Qingfeng take out this Iron Shirt?

Of course, it is to verify the guess in my mind.

Iron Shirt is an external skill specially designed to strengthen muscles, bones and skin. After mastering it, one will be invulnerable to swords and spears. It can be said that a gun will leave a white spot and a knife will cut a white line.

As for the talent of Iron Skin and Bones, it just so happens that it mainly strengthens the tendons, bones and skin. The two are a perfect match.

That's why Gu Qingfeng linked the two together.

He wondered whether he, who was gifted with skin and bones of steel, would be a genius in practicing the iron shirt, or in other words, a genius in practicing external skills!

Anyway, it doesn’t cost to borrow a low-level external martial arts iron shirt.

So Gu Qingfeng borrowed the Iron Shirt secret book.

After leaving the Sutra Library, Gu Qingfeng went straight to the training room.

The training room is where the demon hunters of the Demon Suppression Division practice their skills on a daily basis. It is very quiet and there are formations carved outside the room so they will not be disturbed.

After Gu Qingfeng chose a training room, he couldn't wait to start looking through the Iron Shirt secret book.

About an incense stick later, Gu Qingfeng closed the secret book, and all the secrets of the Iron Shirt training methods were memorized by heart.

The reason why it was so fast was, firstly, because the Iron Shirt was a simple practice method, and secondly, because of the time travel, Gu Qingfeng's soul was slightly stronger than that of an average person, so he had sharp ears and eyes.

After carefully pondering for a moment, Gu Qingfeng began to practice Iron Shirt according to the method in the book.

According to the records in the books, it only takes three days for an ordinary person to get started with the Iron Shirt practice, and one day for a gifted person.

"I don't know how much bonus my iron-clad body can bring."

Practice begins!

After a stick of incense...

"You've already gotten started!? Isn't this too fast?"

Gu Qingfeng's face was filled with shock. He had guessed that having skin of copper and bones of iron would be helpful in practicing Iron Shirt, but he didn't expect it to be so exaggerated. It could be mastered in just one stick of incense?

I'm not practicing a fake iron shirt, am I?

Gu Qingfeng exerted all his strength, and his muscles suddenly became tight and bulged. At the same time, his skin seemed to be covered with a layer of iron blue.

Seeing this hint of iron blue, Gu Qingfeng's expression became even weirder.

"Your body is as hard as iron. This is how you learn the Iron Shirt. You actually mastered it! Keep going. Show me your limit, you have skin of steel and bones of iron."

Gu Qingfeng immersed himself in cultivation again.

An hour later.

"Is it done?!" Gu Qingfeng looked at his skin with a black iron glow in surprise.

"With such an astonishing speed, I'm afraid my iron vest will be fully developed within today! Others need more than ten years of hard work, but I only need one day?

I am indeed a genius in practicing external skills!

It seems that my guess was correct, the Copper Skin and Iron Bones talent is indeed very suitable for the Iron Shirt, and it can even be said that it is suitable for all horizontal training methods. "

As his progress in Iron Shirt deepened, Gu Qingfeng became more and more familiar with the cultivation of external skills. He also roughly understood why he could cultivate Iron Shirt so quickly.

For a normal person, practicing Iron Shirt is like forging a sword. It requires repeatedly burning and hammering a piece of rough iron to remove impurities and refine it into fine iron, and then shaping it and sharpening it.

Gu Qingfeng, who is gifted with skin of steel, is like a sword that has been formed but unopened. He does not need to be forged from scratch by fire or hammering. He only needs to sharpen it to reveal his sharpness!

Gu Qingfeng glanced at the hourglass.

"There are still four hours before the shift change. Four hours should be enough time to practice the Iron Shirt to perfection."