Da Xuan Martial Saint

A letter?

Chen Mu paused slightly in surprise.

Then he walked outside and took a piece of yellow paper from the old servant's hand. After a glance, he couldn't help but laugh in spite of himself.

The yellow paper was scrawled with crooked characters.

[Big brother, you lied. You haven't come to see me for more than a month.]

[But I know big brother must be busy training, so I'll forgive you.]

[I'm doing very well at the martial arts school. All the sisters here like me. Oh, and the master who teaches me martial arts says I have good aptitude and very high comprehension. He says I will become very strong in martial arts in the future, maybe even stronger than big brother, hehe.]

[But don't worry, big brother. I won't bully you, hehe.]

"This girl..."

Looking at the words on the paper, Chen Mu felt a mix of amusement and affection.

Chen Yue had learned to write from him. During the years when there was nothing much to do, he would tell Chen Yue stories and teach her to write. Since they couldn't afford proper writing materials, they would just scratch the characters with sticks in the dirt.

So, this dog's scratch of handwriting was unmistakable; it was undoubtedly written by Chen Yue.

Moreover, his previous judgment seemed correct; this girl's aptitude was indeed slightly better than his, and he never felt that Chen Yue was lacking in comprehension. The child often appeared slow-witted and honest but was actually quite sharp on the inside.

Although the little girl's words might be an exaggeration, overall, she seemed to be doing well, got along well with her fellow disciples, and even had the leisure to write him a letter and send it over, which indicated her situation was very good.

This put Chen Mu at ease.

Indeed, although he had not visited Chen Yue in the Inner City Area, he had always paid attention to her situation and learned that everything was safe.

Now that he had received a letter from Chen Yue, he felt even more relieved.

After some thought, Chen Mu took the letter into the inner room, folded it carefully, and put it away. Then, he went to boil the water to prepare the medicine. Once the medicinal soup was ready, he went to his usual spot, the sand pit he used for Skin Toughening.

The sand in the pit had now turned a reddish hue, filled with a strong medicinal scent; it had been completely permeated by the medicinal soup. The stronger the smell, the better the effect.

Chen Mu dug into the sand again, then lay down inside the pit, covering his body with sand. He then poured the medicinal soup over his lower body before burying his upper body, leaving only his head exposed. Following that, he poured the medicine over the upper body too.

A burning sensation immediately spread throughout his body.

A tingling numbness.

Until the medicine cooled, he poured again, repeating the process several times until the medicine was fully used up. Then, Chen Mu abruptly climbed out of the sand pit.

Since reaching Major Achievement in Skin Toughening, the internal and external application of the medicinal soup no longer had as strong an effect on him as at first. Initially, his entire body would be so numb that he could barely move for a short time, but now, after enduring and refining, he could easily get up, feeling only a slight soreness and weakness.

Once Chen Mu had washed the mud and sand off his body, he was fully recovered.

"That should do it."

Chen Mu took a deep breath and returned to the bedroom to adjust his state.

After about a month, he was finally about to bring the Golden Jade Skin Toughening Technique to perfection. It was the perfect time to see how much of a gap there was between the perfection of his Skin Toughening and the natural Copper Skin of Zhang Xiangshen's son.

Hum!!

As he chose to advance on the system panel, a surge of hot Qi-Blood exploded inside Chen Mu's body.

It felt like a boiling wave radiating from within to outward, penetrating every bit of his skin, moving in and out as if billions of steel needles were continuously piercing through every pore.

This was already the third time enduring such excruciating pain. Chen Mu was much more resilient than the first two times; the first time, he had passed out, and the second, he nearly bit through a pillow, tormented to the point where he couldn't move his body at all, unable to make a sound.

But this time, he could bear it.

Billions of scorching steel needles, penetrating continuously through every part of the skin, left a burning sensation on the skin's surface, making his entire skin sizzle with heat to the point of turning red, gaining a faint glimmer like reddish jade.

After an indeterminate amount of time, that excruciating pain finally began to gradually subside.

It was as if all impurities had been washed away, and the mercury had been sublimated. Every inch of his body seemed to emit a sound of pleasure, as if after enduring the difficult Skin Toughening, he had finally broken out of his cocoon into a butterfly, undergoing a transformative change.

When Chen Mu sat up from the bed and looked at his body, he could see that his skin, unlike before, didn't have a hint of roughness, but it did possess a sturdiness comparable to that of stone.

Bang!

Chen Mu raised his hand and fiercely slapped down on the table, his palm sounding like it was covered with a thick layer of leather, emitting a dull thud, while the table shook and even began to crack at the edges!

"This is Skin Toughening Perfection."

Chen Mu let out a long breath, able to feel his own transformation. The change was much greater compared to Major Achievement in Skin Toughening. Although his skin looked unchanged on the surface, it now concealed the toughness of gold and jade, as if he were wearing a suit of Gold and Jade Soft Armor.

Those bandits who had never trained in martial arts, or those who only knew a few disorganized moves, would find it very difficult to cut through his skin, not to mention that materials like quicklime powder, unless it got into the eyes, could basically be ignored.

Skin Toughening Perfection!

It meant that the strength of the skin could now withstand the enhancement of muscle power.

Skin Toughening first, then Body Refinement. This order wasn't arbitrary; if Body Refinement came first and the muscles suddenly became too strong, then upon exerting force, it was likely that one's own skin would not be able to withstand and would tear apart.

Thus, it was essential to have resilient skin to support further hardening and strength enhancement of muscles to unleash power freely.

This realm was actually quite formidable outside, and reaching this level in a gang would place one's status on par with having a Blade Technique at Major Achievement, or perhaps even higher than just Major Achievement.

Those who could train their Skin Toughening to Perfection usually had some practice in Blade Technique or Swordsmanship as well, whereas those who were skilled in techniques might not have the opportunity to train their Skin Toughening to Perfection, as the former only required a blade to practice, while the latter needed a significant investment of Silver Coin.

"However, indeed, I can't compare to someone like Zhang Xiangshen's son, born with Copper Skin…"

Chen Mu clenched his fists, felt the strength of his skin, and then shook his head slightly.

If one considered Zhang Xiangshen's son's Copper Skin to have a strength of 'ten,' then his own skin's strength was probably only around 'seven.' The difference was quite noticeable.

This difference was determined by physical constitution and had little to do with the Skin Toughening Method itself. With something like the Golden Jade Skin Toughening Technique, this level was the limit. Chen Mu estimated that even if he continued to cultivate according to this practice method, internally and externally, it probably wouldn't have any effect anymore.

Because his skin had completely adapted to the two types of medicinal baths from the Golden Jade Skin Toughening Technique.

Chen Mu summoned his system interface to test it out, and sure enough, Perfection was the limit for the Golden Jade Skin Toughening Technique, and he couldn't advance further. At most, this technique could only refine his skin to this extent.

Having reached this step.

If he wanted to train his skin further, the only option left was to switch to a different recipe.

But most people would not do so because even if one found another Skin Toughening Method to cultivate and spent another two or three years to reach Perfection, it might only improve the strength of the skin to 'nine.'

It might seem like a significant improvement, but for them, devoting two or three more years could mean that they would never have the chance to break through to realms like Tendon Changing or Bone Tempering.

Usually, only those who were naturally endowed with Copper Skin, or those with exceptional roots and rapid progress, the heaven-sent prodigies unconcerned about future advancement, would be willing to spend extra time solidifying their foundation.

"The next step for Body Refinement, I don't have a method at hand yet, but for Skin Toughening…"

Chen Mu took out a small booklet from his house.

"Iron Sand Skin Toughening Method"

For him at present, it was somewhat troublesome to find a Body Refinement method, but getting a basic Skin Toughening method was very easy. He had directly obtained one during his spare time at the City Defense Division.

"It's still worth a try."

For the average person, practicing multiple Skin Toughening methods meant slower progress as the strength of their skin increased because trying to achieve results with another method when the skin was already tough often led to diminishing returns.

He, however, was different.

Looking at his cultivation progress with the Golden Jade Skin Toughening Technique, his speed of advancement was only getting quicker. The stronger the skin, the more powerful the medicinal effects it could withstand, even to the point of force-feeding in a single day!

If that were the case, it was unquestionably worth a try, for even those who had achieved Minor Achievement in Body Refinement might not fare well against someone who had developed Copper-Steel Skin.

Take someone like Zhang Xiangshen's son with his innate talent and formidable Copper Skin; such a person would be very difficult to kill unless confronted with someone who had reached Body Refinement Perfection and had deadly Sword Momentum, enough to break through his defense with a single strike.