Shikkotsu Forest

At the border of the Land of Fields, a man suddenly fell from the sky. He smashed through two or three branches before hitting the ground. They softened his fall somewhat, but it was clear he was badly hurt.

The mountain had long been known to the people nearby as the Mountain of Evil. Some said the forest was made of bones; others claimed the mountain could move. Rumors abounded, and many who ventured inside never came back out. In time, no one dared go there anymore.

"...Hey... system... have I... arrived?"

The man who had just fallen was none other than Feng Yao, who had narrowly escaped with his life. He wondered if the system had screwed him over.

He had been on the ground when he was transported, but somehow his landing point after the transfer had been in a tree. After such a long escape, and without any food...

Feng Yao was already at the end of his rope. He couldn't even hold on to the trunk and fell, smashing through several thick branches on the way down. He figured he'd broken a rib.

"Host, you have arrived at Shikkotsu Forest."

But Feng Yao had no strength left. Once he learned he was safe, his head grew even foggier. At last, he slumped over and passed out.

About two or three hours later, a slug with blue stripes emerged from the ground. It slowly crawled over to Feng Yao and examined him closely.

"How did this human get in here? He looks badly hurt. I hope he doesn't die here. Then someone else might come in."

As it spoke, it climbed onto Feng Yao. A gentle energy flowed from the little slug and entered his body.

The exhaustion and injuries in Feng Yao's body quickly faded. He had a dream, a very long dream. In it, he became the strongest in the Shinobi World, found Earth, returned to China, and lived happily with his parents.

"Whoa! Hah... hah... did I pass out?"

Feng Yao woke from his dream, and there seemed to be tears at the corners of his eyes. He looked around in surprise, realizing that his injuries and fatigue had completely vanished. But there was a serious side effect...

That's right... he was hungry.

During the escape, he'd been too tense to think about food. Now that he'd slept and recovered, his stomach was rumbling like thunder, reminding him that he needed to eat.

"Yes. You were unconscious for eight hours. A slug treated your injuries."

Feng Yao looked around, but there was no sign of the slug. He couldn't worry about that now. He needed to fill his stomach first.

He got up and headed deeper into the forest. Whenever he spotted something edible, he stuffed it into his mouth, whether it was clean or not.

Leaves, lettuce, lilies...

"That human... I saved him, and he's stealing my food."

Feng Yao didn't know that he'd just earned himself a bad review from the Katsuyu Sage. He kept eating heartily while searching for traces of the Katsuyu Sage.

"System, once I finish my mission, I get another chance to draw a reward, right? What can I get?"

Feng Yao asked silently as he chewed. Honestly, with the system's restriction on ninjutsu, it probably wouldn't give him something like a jutsu. The system could make him master those directly.

"The lottery system allows the host to obtain abilities or items from other worlds. It could be an insanely powerful finishing move, or it could be a toothbrush."

The system's emotionless voice continued, nearly making Feng Yao choke on his food. He'd always had terrible luck with lotteries. When he played games back in China, he always had to rely on the guaranteed rewards.

In the Naruto world, he'd drawn Senjutsu, which he couldn't use at all. The system's missions were all bizarre, like challenging opponents far above his level. Feng Yao had grown wary of its draws.

"I feel like I don't even need to draw. You'll probably give me a toothbrush..."

Feng Yao said sourly.

"Very well. Then I'll give the host a toothbrush."

"Wait... wait, I was joking! I'll draw. I have to!"

Feng Yao changed his tune faster than turning a page. He had no idea what he might get, but people needed dreams... Otherwise, how were they any different from salted fish?

"Very well. Beginning the reward draw for the host from all worlds."

Feng Yao nervously swallowed. Less than two minutes later, the system spoke again.

"Congratulations, host. You have obtained the Six Powers. Would you like to learn them?"

"The Six Powers? That's Taijutsu, right? Can I use it after learning it?"

After seeing how treacherous the system could be, Feng Yao was wary.

"Gunshot, Rankyaku, Shave, Kami-e, Moonwalk, and Iron Body are collectively known as the Six Powers in One Piece. They are a type of combat technique, a form of Taijutsu that surpasses the limits of human physical ability."

"Rest assured, host. This system restricts ninjutsu and Taijutsu from the Naruto world. The Taijutsu obtained in this draw is not from that world, so you can use it."

Only after hearing this did Feng Yao let out a sigh of relief. He waved his hand grandly.

"Learn it. Why wouldn't I?"

A flood of knowledge poured into his mind, making his head ache. But after a short while, Feng Yao realized that he had mastered the Six Powers and could use them with ease.

"Damn system, if you'd given me this earlier, would I have had to get beaten up so badly?"

"If the host couldn't handle the earlier situation, then he could only be an ordinary person. Even with this system's help, an ordinary person could never become a Child of Destiny who surpasses this world."

Feng Yao fell silent. It was true. Compared with the protagonists who would become absurdly powerful later on, his current strength wasn't worth a damn. If he didn't grow quickly, all he could do was watch them from behind.

"Moonwalk!"

Feng Yao burst forward with his legs, moving at high speed. The technique increased his mobility and let him change direction while falling through the air. Using it, he searched the mountain for Shikkotsu Forest.

After about half an hour, he spotted a bamboo grove halfway up the mountain. No, it was more like a forest of bones. Aside from a few scattered bamboo stalks, enormous bones stood all over the ground, along with the skeletons of many animals.

A huge stone monument bore the words "Shikkotsu Forest." The bones here were pure white and exceptionally clean, but Feng Yao still felt a chill run down his spine.

He walked in, but there wasn't a single slug in sight. Curious, he asked,

"System, didn't you see where the slug that treated me went?"

"It merged into the ground. Its exact location is unknown."

After silently complaining about the system's irresponsibility, Feng Yao had to figure things out himself.

"Esteemed Katsuyu, I'm Feng Yao, a ninja from Konoha. I know you saved my life. Would you come out so I can thank you in person?"

His voice echoed through the forest, but no one answered. Feng Yao had no choice but to sit cross-legged and wait, continuing to study the Six Powers. After a long while...

"Now that you're all right, leave at once. This is no place for you. And don't go telling people about it."

A voice came from all around him. It sounded very gentle, but the speaker was clearly ordering him to leave.

"What the hell, system? You said I had an opportunity here. They're already kicking me out. Can I rely on you or not?"

"Stay calm, host. An opportunity has to be earned. Here's a medical text. You'll have to earn it for yourself."

Something heavy suddenly appeared in Feng Yao's arms. He took it out and saw the Eastern Medical Canon. His face was a picture of bewilderment.

"What does this mean?"

"The Katsuyu Sage excels at Medical Ninjutsu and healing. This medical canon is the culmination of thousands of years of Chinese knowledge. It would be irresistible to anyone who understood medicine."

Feng Yao understood. The Katsuyu Sage had never appeared in Naruto, and very little was known about it. But among the Three Great Summoning Creatures, Katsuyu's abilities were indeed mainly focused on healing.

"Lord Katsuyu, I know you have always been skilled in medical techniques. I have a medical book here, the culmination of thousands of years of knowledge from a great nation. I'd like to propose a trade."

As he spoke, the ground in front of him began to writhe. At last, a slug the size of an adult emerged.

"A medical book passed down for thousands of years? I didn't think any country in the world had a history that long."

Seeing that Katsuyu had appeared, Feng Yao smiled faintly. Her arrival meant there was hope. He held out the book.

"Lord Katsuyu, you'll understand once you take a look."

Katsuyu took the book with her soft, squishy body. At first, she flipped through a few pages as if testing it out. Then she became more and more engrossed, and increasingly excited.

"Oh! You can do this without Medical Ninjutsu?"

"So it can be done this way, too!"

"Do these medicinal herbs exist in this world?"

Seeing that the Katsuyu Sage seemed captivated by the Eastern Medical Canon, Feng Yao cleared his throat and calmly snatched it back from her. It took quite a bit of effort...

"Let me look at it some more..."

"Lord Katsuyu, I meant to give you this book, but I have one small request. I hope to learn Shikkotsu Forest Senjutsu and become a sage."

Feng Yao waved the book back and forth in front of Katsuyu before making his request with a sly smile. Katsuyu froze when she heard him. Feng Yao frowned.

"What, is that not possible? Then this book can only..."

"No, no... it's not that. It's just that learning Senjutsu is dangerous. You clearly don't have enough chakra. Natural Energy would assimilate you directly."

Feng Yao was stunned. It was true that the system had boosted his chakra once, but even so, he didn't have half as much as Naruto. He couldn't yet withstand the impact of Natural Energy. Just as he was caught between a rock and a hard place...

"Congratulations, host. You have triggered a limited-time reward mission. Your reward is granted in advance: three times as much chakra. Mission requirement: learn Sage Mode within one week."

Motto: As someone who can stand against the protagonist, how can you let a little slug look down on you? Go and astonish the sage!

"Something this good can happen? Are you really the same system I know? Did you switch places with someone?"

"Doubting the host is equivalent to doubting this system. Please complete the mission as soon as possible."

As soon as it finished speaking, Feng Yao's chakra surged. In an instant, he had reached the minimum requirement for training in Sage Mode. Katsuyu was astonished, wondering why his chakra had suddenly increased so much. Facing her questioning gaze...

"Ahem. I was hiding my strength just now. This is my real chakra level. I should meet the requirements for learning Sage Mode now, right?"

"Hmm... that's true. But I must warn you that training in Sage Mode is extremely dangerous. Are you sure you want to do this?"

"Yes, I'm sure. Sorry for the trouble, Lord Katsuyu."

As he spoke, he handed over the book first. Katsuyu saw how considerate Feng Yao was and took it without hesitation, then led him into Shikkotsu Forest. As they walked, she said,

"If you want to learn Sage Mode, do you know what Senjutsu is?"

Feng Yao listened to Katsuyu's question and answered fluently.

"Senjutsu is the art of absorbing Natural Energy and combining it in a certain ratio to create Senjutsu Chakra. It greatly enhances your ninjutsu, Taijutsu, and genjutsu, right?"

"Yes. For beginners, the best way to sense the Natural Energy of my Shikkotsu Forest is to remain completely still in a suitable place, cease all activity, and harmonize with nature. I'll take you to the sacred grounds of my forest, where Natural Energy is most abundant."

After walking with Katsuyu for about half a teacup's time, they finally reached a circular building made of various bones. It was completely sealed and looked rather frightening from the outside.

"These are the bones of powerful summoning creatures I defeated in the past. I used them to build the Bone House. It blocks out all outside disturbances. Neither light nor sound can pass through, making it easier for you to sense Natural Energy."

"Thank you, Lord Katsuyu. Can I try it now?"

Feng Yao couldn't wait any longer. On the one hand, he genuinely wanted to master Sage Mode; on the other, he didn't have much time. With Katsuyu's permission, he entered the building.

After going inside and closing the door, Feng Yao's first impression was silence—absolute silence. In the pitch-black, sealed space, he could almost feel the blood flowing through his veins and his heart beating. In the darkness, even the slightest sound of his breathing seemed amplified without end.

Feng Yao felt his way around and sat down. His hands were already damp with sweat. The utter silence of the room put tremendous strain on his mind. He tried to sense the Natural Energy.

But within minutes, his own pounding heartbeat and breathing made him anxious and restless. He even wanted to tear out his heart and crush his throat just to stop them from making noise.

Just as Feng Yao was about to break down, the door opened. Light poured in.

"Haah... haah... haah... Lord Katsuyu..."

Feng Yao's eyes were bloodshot, and he looked as though he'd just been pulled out of the water.

"Ah, come out for now. This isn't something you can accomplish all at once."

Katsuyu helped Feng Yao outside. Honestly, Feng Yao had trained his mind well. His mental resilience was excellent, as his calm response in their earlier fight had shown. Yet in the Bone House, he had broken down in a short time. Most people, especially those with weaker minds, would fare even worse. Besides the room's clever design, a technique had been added to make people feel anxious and unsettled.

Only by maintaining a calm mind and stable spirit under those conditions could one sense Natural Energy in Shikkotsu Forest. That was how the forest's Sage Mode was learned.

Feng Yao was helped outside, where he slumped down. He turned to the Katsuyu Sage beside him and asked,

"Lord Katsuyu, how long was I inside just now?"

Inside the room, Feng Yao couldn't even tell where he was, let alone sense the passage of time. He had no idea how long he'd been there.

"About ten minutes. That's quite good—better than I expected. It seems you have more talent than I thought."

"Only ten minutes...? It felt like a century. How long do I have to last in there to sense Natural Energy?"

"I estimate that you'll need to stay in the Bone House for a whole day while remaining conscious."

Hearing this, Feng Yao jumped up and charged back into the building without looking back. A whole day? He only had one week, and he'd lasted just ten minutes. If he didn't push himself, he'd be dead.

Katsuyu watched Feng Yao rush into the house. Ten minutes later, she went in and dragged him back out.

"Hah... how was it...? Did I... last a long time?"

Feng Yao looked just as bedraggled as before.

"About ten seconds longer."

"..."

Feng Yao rested for a few minutes, then plunged back inside. And so it went: in and out, over and over.

"Keep it up! You can last twenty minutes now."

Katsuyu spoke to Feng Yao, his eyes bloodshot, as she nibbled on a leaf.

"You're close to an hour now. Have you trained in Sage Mode before?"

Katsuyu looked at Feng Yao, who was sprawled on the ground resting, her mouth dripping with slime.

"Are you a summoning creature in disguise? You managed to stay in the Bone House for three hours after only two days."

Katsuyu dragged Feng Yao outside, making a sarcastic remark. This had far exceeded what the Katsuyu Sage had expected.

It was already evening. Feng Yao was mentally exhausted. He'd trained for long hours over the past two days, sleeping only one hour each night. He even had dark circles under his eyes.

"Why are you pushing yourself so hard? You won't die if you train poorly. But if you keep training like this, you really might."

Katsuyu handed him some leaves. Feng Yao silently answered in his mind: If he failed to train properly, he really would die. At this rate, he couldn't possibly finish within a week.

"Damn it, system. I knew you were up to no good, always thinking of ways to screw me over. I knew you weren't being nice when you suddenly boosted my chakra. I don't care—give me more time."

"The host seems to be talking in his sleep. This system's missions are always final. If the host cannot complete this mission, I'll have to follow the rules."

"I know! You'll kill me, right? Can't you come up with something new?"

So Feng Yao could only ask the Katsuyu Sage for help again.

"Lord Katsuyu, I don't have much time. Is there a shortcut I can take, or some way to speed up my training?"

Katsuyu frowned at his words. Honestly, she'd only wanted Feng Yao to try so he'd realize it was too difficult and give up. But seeing how talented and hardworking he was, she genuinely wanted to pass on Shikkotsu Forest Senjutsu to him now. She didn't want him to take a shortcut, because it would be very dangerous.

"Take your time. If you use a shortcut, the danger will be more than ten times greater. With your talent, you could probably master Sage Mode in less than a month. Why rush?"

Katsuyu earnestly tried to persuade him. Feng Yao could only smile bitterly. He knew she meant well, but he really did have his reasons.

"Lord Katsuyu, please. I have to speed up my training. I don't know how to explain it, but... my life depends on it."

"...Is it really that serious? Hmm... then wait a moment."

Katsuyu pondered for a while, as if making a decision. Suddenly, all of Shikkotsu Forest began to tremble violently—or rather, the entire mountain did. Rocks and soil tumbled down as a slug, seemingly magnified countless times, crawled out of the mountain. More accurately, the whole mountain stood on its back. This enormous slug was the Katsuyu Sage's true body.

The other versions, including those summoned by Tsunade and Sakura, were only fragments of the Katsuyu Sage. Feng Yao finally felt the true power of a sage. The Natural Energy surrounding her with every movement was enough to lift a mountain.

"Feng Yao, come over here, by my head."

The Katsuyu Sage spoke again. Her true body had an overwhelming presence, and Feng Yao couldn't bring himself to resist. He obediently ran over.

The Katsuyu Sage suddenly spat a mouthful of slime onto the ground. It didn't seem to be the corrosive kind.

"This is the mucus from inside my body. Unlike ordinary slime, it contains part of my body that absorbs and gathers Natural Energy. If you spread it over yourself, you'll be able to sense and gather Natural Energy, then try to control it."

"...Slime... I see. Thank you, Lord Katsuyu."

Honestly, Feng Yao felt a little repulsed by the slime. But for the mission, and to unlock Sage Mode, he'd do it!

After gathering the slime, Feng Yao immediately ran back to the Bone House. This time, though, the Katsuyu Sage sent a clone in with him.

To prevent Feng Yao from being assimilated by Natural Energy, she would absorb it from his body when necessary.

After Feng Yao spread the slime on himself and tried again, he really did sense a powerful energy outside his body. Guided by the slime, it flowed into him. Feng Yao quickly tried to combine this external Natural Energy with his own spiritual and physical energy, but the two were forced apart almost at once. His body filled with an enormous amount of Natural Energy.

His eyes narrowed, two fleshy lumps emerged from his head, and his body seemed to shrink. The nearby Katsuyu leaped onto him and squirmed, absorbing the Natural Energy from Feng Yao's body.

Feng Yao gradually returned to normal. He touched the skin the Katsuyu Sage had sucked red and suddenly thought of something.

"Lord Katsuyu, I'll absorb the Natural Energy first. Then you can draw some of it out—but don't draw it all out. Let me try fusing what's left."

"Mm~ That might work too. Give it a try."

The man and the slug spent three days and three nights in the dark room. Aside from occasionally coming out to rest and eat, they hadn't taken a break.

"I feel like I'm almost there. The last time I tried fusing Natural Energy, I was just a little short."

"Mm, I never thought you'd master it in such a short time. I wish the lord who made a contract with me had been as talented as you."

"Oh? What happened to her?"

"The first time she entered Bone House, she got so worked up that she went berserk after just a minute. She even smashed her way out and wrecked my Bone House."

The person the Katsuyu Sage was talking about was probably Tsunade. Though she was a medical ninja, Tsunade was very much a strong-willed woman, and she had a fiery temper. Keeping her in such a silent environment would have been a tremendous torment. No wonder she hadn't managed to master Sage Mode of Shikkotsu Forest.

On the sixth day of his training inside Bone House, a powerful, subdued presence emerged from within. With a bang, the door exploded, and a figure sent a mighty punch into a massive bone standing in the distance, shattering it to pieces.

A white-haired boy stood atop a boulder. His eyes were cherry-red, with pale blue eyeshadow at their corners. It was Feng Yao, now in Sage Mode.

Sage Mode changed his appearance dramatically: his eyes, eyeshadow, and even his hair all turned white. Once he entered Sage Mode, Feng Yao felt as if his whole body were brimming with strength and had nowhere to release it, so he had run outside to let some of it out.

Feng Yao was very pleased with the blow he had just landed.

"Ahhh! What did you do, you brat? Couldn't you open the door properly? My Bone House!"

At the sound of that, the imposing air Feng Yao had just exuded collapsed in an instant.

"Ahem... Lord Katsuyu, don't be angry, don't be angry. I'll fix it. I was just too excited."

After hearing his apology, the Katsuyu Sage looked much better. It hadn't really been angry, though. Seeing Feng Yao master Sage Mode of Shikkotsu Forest made it very happy.

Feng Yao sat on the ground, patiently sensing the abilities he had in Sage Mode. In this state, his mind was exceptionally powerful. Even complicated matters or extreme situations couldn't make him feel agitated.

At the same time, the Natural Energy in Sage Mode heightened his body's vitality, agility, and defense. He could also use Natural Energy to extend his sensory range. Now he could sense the Katsuyu Sage's true body beneath his feet, something he hadn't been able to do before.

Most importantly, there was the process of gathering Natural Energy. In Sage Mode from Mount Myoboku, one had to stand still for a while to gather Natural Energy. This Sage Mode from Shikkotsu Forest required even longer to gather it, though the Katsuyu Sage said that practice would shorten the time.

But it made up for that with its long duration. Sage Mode from Mount Myoboku lasted around five minutes. Naruto could use Shadow Clones to gather chakra and sustain it, which worked fairly well, but Feng Yao's Sage Mode could last at least twenty minutes.

In terms of sustained combat, Sage Mode from Shikkotsu Forest was far ahead.

And now he could finally experience how powerful the system was. When he used chakra, it changed in nature according to the Senjutsu he wanted to perform. He had now mastered and could use every Senjutsu that had appeared in Naruto. He spread his hands and began forming hand seals.

Sage Art: Yin Release Lightning Dispatch

This was one of the Yin-Yang Release techniques in Naruto. With Senjutsu Chakra empowering it, it could unleash even more terrifying power. The user could release black lightning from both hands to attack enemies.

The black lightning shattered the few massive bones still standing around them. Even the Katsuyu Sage behind him couldn't help marveling at the power of the Senjutsu.

After trying out that technique, Feng Yao still wasn't satisfied. He wanted to try some others, too.

Sage Art: White Rage Technique

Feng Yao puffed out his belly and spat out a phantom dragon. Its claws held a pearl, which emitted a blinding light before exploding. Through vibration, this technique could rob others of their five senses and damage their hearing and vision.

As soon as he finished using it, Feng Yao realized that his own Senjutsu had... blinded him. Fortunately, he had only slightly damaged his corneas, and the Katsuyu Sage could heal him.

He deactivated Sage Mode and obediently sat down to let the Katsuyu Sage treat him, cursing inwardly all the while.

"Damn it, this system really was a nine-yuan, free-shipping special. The Senjutsu doesn't distinguish between friend and foe?"

"That's because the host is stupid. What does that have to do with this system? This Senjutsu requires the user to meet certain conditions. Besides, this system only lets you use every Senjutsu. It doesn't reduce their side effects."

Feng Yao was left speechless. He really had gotten a little carried away with excitement. When Kabuto had used this Senjutsu, he had shielded himself from the intense light with a snake's cornea. And Feng Yao didn't have a snake's cornea...

"Then why didn't you warn me earlier..."

"I thought the host had realized. Sorry. I overestimated your intelligence again."

The system's infuriating tone made Feng Yao furious all over again. But at least he had succeeded. At last, he had the strength and means to protect himself in the Shinobi World.