After Katsuyu's explanation, Yue Yan also understood why granite - made bricks were needed.
The Shikkotsu Forest was constantly pelted by highly corrosive acid rain. Although one had to face this acid rain during Sannin Mode training, there were breaks. At such times, a place to shelter from the acid rain was necessary.
Katsuyu didn't know why granite - made bricks weren't corroded, but through the numerous attempts of previous Sannin Mode learners, it was found that they weren't affected by the Shikkotsu Forest's acid rain.
Katsuyu was unaware, but Yue Yan, who had studied chemistry in his previous life, knew that the main component of granite was silicon dioxide, which was also the main component of glass. Common strong acids like sulfuric acid and hydrochloric acid were stored in glass containers. To dissolve glass, hydrofluoric acid was needed, also known as bone - melting acid. Few living things could survive in this acid. So, the acid rain in the Shikkotsu Forest definitely wasn't hydrofluoric acid.
Yue Yan went to the stone market, bought a large quantity of granite bricks, sealed them in a Scroll, and then, with a spare set of clothes, asked Katsuyu to reverse - summon him to the Shikkotsu Forest.
As soon as he arrived in the Shikkotsu Forest, Yue Yan felt a stinging pain all over his body. The culprit was the light cyan rain continuously falling from the sky.
Feeling the excruciating pain of his skin being corroded, Yue Yan gritted his teeth and opened the Scroll. He quickly built a shelter as fast as he could in this life and then crawled inside.
Looking at his body covered in blood with large areas of skin corroded away, Yue Yan grimaced mainly due to the pain, as he wasn't a masochist with an interest in enjoying pain.
"Hey, Yue Yan's really fast! He's already got a shelter up. The last guy had to go back and forth a few times before he could build one."
At this time, Yue Yan noticed that the little Katsuyu who had just spoken had separated from the blue ground beneath his feet. This meant that Yue Yan was standing on Katsuyu's body.
Through the opening of the shelter, Yue Yan looked into the distance and saw an endless expanse of blue - white.
"So, this is big sister Katsuyu's main body. It's truly massive!"
In the original story, the Turtle Island of the Cloud ninja village and the Ten - Tails were already huge. But compared to Katsuyu's main body, it was like putting a baby next to Shaquille O'Neal, a complete midget.
Apart from Katsuyu, there was no other life in the Shikkotsu Forest. There was only a gray sky and never - ending acid rain.
In addition, there were various huge bones standing in the Shikkotsu Forest, towering like mountains.
Ribs, spines, leg bones, etc., all proved that these creatures were extremely large when they were alive. Yue Yan even saw a bone in the distance whose size was impossible to estimate. If it were still alive, it might be tens of thousands of meters long. It was unimaginable what kind of power could have killed it.
To be honest, after defeating several hundred enemies in a previous battle, Yue Yan couldn't help but feel a bit proud. However, when he saw these bones, that pride was completely shattered.
Noticing that Yue Yan was in a daze, Katsuyu crawled onto his head, with her little antennae wiggling.
"Are you curious about those bones, little Yue Yan?"
"Indeed, I'm a bit curious."
"I don't know either. Those bones were already there when I gained consciousness."
Noticing the happiness in Katsuyu's words, Yue Yan couldn't help but raise his eyebrows.
"Big sister Katsuyu seems very happy."
"Yeah, after all, I've always been the only one here in the Bone Forest. You're the second human to come here, little Yue Yan."
"Really?" Yue Yan looked at the hazy Bone Forest in the distance and felt a bit emotional. After all, loneliness is the most unbearable thing. It can drive any sentient being with self - will crazy.
"Although I forgot where I heard this sentence, I want to give it to you. May you, the loneliest but eternal one, be able to listen to all the stories in the world and sing them down to prove that all sentient beings have come to this world."
After a brief moment of stunned silence, the little antennae on top of Katsuyu's head that was lying on Yue Yan's head wiggled even faster than usual. Yue Yan could also clearly feel that Katsuyu's main body under his feet was trembling.
"Little Yue Yan, I really like this sentence of yours. I'll always remember your story and sing it down."
"Okay, I believe you, ma'am."
After saying that, Yue Yan took a deep breath, stepped into the area covered by acid rain, and sat down cross - legged.
He felt the pain caused by the acid rain constantly corroding his body while listening to Katsuyu explain the training method of the Sannin Mode.
The methods of training Senji in the Bone Forest, Mount Myoboku, or the Ryuchi Cave are different. However, they all require the trainees to empty their minds and immerse their spirits in nature.
With Calyrex's Nature's Embrace, Yue Yan had a high compatibility with natural energy, and it was not difficult for him to empty his mind. Therefore, he quickly immersed himself in the training.
This feeling was so wonderful that it was as if Yue Yan had merged with nature and become a part of it. He had transformed into a gentle breeze passing through the mountains, a wheat ear feeling the sunlight in the paddy field, or a gurgling river flowing in the mountain stream.
Even the pain of his body being corroded by the acid rain didn't seem so bad.
Time flies when cultivating immortality. Well, this saying doesn't really fit this world though (a Chinese saying meaning time passes quickly when cultivating immortality). When Yue Yan was awakened by Katsuyu, several hours had passed.
As soon as Yue Yan stood up, he found that his skin had been completely corroded and fallen off. When he raised his palm, he could clearly see his bones. Thanks to his own strong recovery ability and the enhancement from sage Katsuyu's main body, otherwise, he would have been dissolved and become another set of bones in the Bone Forest.
Yue Yan walked back to the shelter, leaving a bloody footprint with each step. No longer feeling the acid rain, he finally let out a long breath, and then all he felt was pain, excruciating pain, almost like having his tendons torn and skin peeled off.
Yue Yan even felt that the pain of being cut into a thousand pieces was far less than this.
Yue Yan didn't even dare to imagine what he looked like now. He guessed that if he took one look, he wouldn't be able to sleep tonight.
Maybe he looked like a person with the skin peeled off, exposing the muscles.
Just as Yue Yan's thoughts habitually drifted, countless little Katsuyus split out from under his feet and wrapped his whole body inside.
Feeling the different sensation from the medical energy released before, Yue Yan knew that it should be natural energy.
At this time, the little Katsuyu also began to explain.
"Little Yue Yan entered the cultivation state very quickly just now and successfully established a connection with the natural energy in his body. That's why I can help you recover quickly now."
As she said that, Katsuyu also asked curiously.
"By the way, why did you use that posture, little Yue Yan? As long as your body is in contact with the acid rain, the posture doesn't matter. The last person who practiced the Sannin Mode almost curled up into a ball."
"Um, doesn't Sister Katsuyu think that posture for cultivating the Sannin Mode is really cool?"
Yue Yan explained awkwardly. After all, he couldn't tell Katsuyu that it was just how people practice cultivating immortality.
"Really?"
Katsuyu tilted her head, seemingly unable to understand where the coolness was. But she soon stopped caring about it and then said, "Little Yue Yan has a very high compatibility with natural energy. It seems that the natural energy favors you a lot. Originally, I estimated that it would take you three years to master the Sannin Mode, but now it seems that the time can be shortened a lot."