A Way of Training

After Konan put away the Explosive Tags, Nagato controlled Pain to pick up Tsunade and Hinata, then jumped down from Cerberus.

Seeing this, Konan gave Nagato a long look. When she saw that there wasn't a trace of confusion in his eyes, she followed the Pains and jumped down too.

"I believe in you!" she said to Nagato as she leaped from Cerberus's back.

A smile appeared on Nagato's face. He thought, It feels pretty good to have someone trust me.

He was a man destined to become a god. Surely he wouldn't die in a place like this?

Probably...

"All right, let's keep going," Nagato said to the little slug still lying on Cerberus's back, his heart full of positivity.

The little slug, who had been standing off to the side, stunned by the six hundred billion Explosive Tags, hurriedly spoke up. "Wait, I think we should think this over again."

At Nagato's command, Cerberus broke into a run on all fours.

"What's there to discuss? I've already made up my mind," Nagato said nonchalantly.

"Don't you think you made that decision too hastily? People really can die learning Senjutsu!"

The slug suddenly began worrying about Nagato's safety.

"It's fine. I won't die." Nagato had complete confidence in himself.

"Did you really understand what I said earlier?! No one has ever learned Senjutsu in Shikkotsu Forest. Not one!" The little slug's voice rose an octave, and it sounded a little frantic.

"I know. How did you know I was the zero? My codename in the Akatsuki is Zero. You're a clever little thing."

Nagato curled his lips into a smile. The more frantic the slug got, the more reassured he felt.

"Huh? That's not what I meant! Please think it over again! You don't want to die, do you?"

The little slug bounced in agitation, like a spring.

Nagato looked at the slug with understanding and thought, This one's a homebody. Then he shook his head. "Honestly, you're not the one who's going to die, so what are you afraid of? Besides, the whole of Shikkotsu Forest will be buried with me. I won't be losing out."

"That's exactly why I'm worried~~!!!" The slug started bouncing wildly on Cerberus's back, as if it had unlocked some new skill. "Please, I'm begging you. Give up on Senjutsu. It's way too dangerous!"

The slug's behavior really moved Nagato. It was genuinely worried about his safety! Probably...

Nagato nodded and answered briskly, "Want me to give up? You should give up on that idea!"

The slug threw its head back in exasperation, its four antennae pointing skyward as it let out a silent, upward-looking sigh. It seemed to have no desire to talk to Nagato anymore.

Gradually, all Nagato could hear was the sound of Cerberus running.

The green mist around them grew thicker and thicker. Every so often, they saw a human skeleton pitted and eroded by corrosion, making the place seem especially dangerous.

"Are these green things in the air what's left after the acid evaporates?" Nagato asked, spreading his hands and feeling the fine, prickling pain against his bare upper body.

As soon as he finished speaking, Nagato shut his mouth. A burning pain had struck his nose and throat, and tears began to well in his eyes.

"Impressive, isn't it? This is still mild. The closer you get to the real Shikkotsu Forest, the worse it gets. I suggest you give up as soon as possible." Seeing that Nagato had been forced to close his eyes, the slug hurried to take the opportunity to persuade him.

Nagato placed a hand on the slug and used the Human Path's ability to speak with it. "The real Shikkotsu Forest? No wonder you didn't want Tsunade to come in. We're not at the place where I can train in Senjutsu yet?"

Through Cerberus's eyes, Nagato saw that the acid mist around them had grown as thick as spiderwebs. He frowned and controlled the Human Path in the distance to walk toward Tsunade.

"What are you trying to do?" the slug asked warily at once. It seemed to have noticed the Human Path's movements.

Nagato didn't answer. Instead, he used the Summoning Jutsu.

He summoned the Asura Path to speak in his place. "You'll find out in a moment. Don't worry, I won't do anything to Tsunade."

Meanwhile, the Human Path pressed a hand to Tsunade's head and began reading the information in her mind.

He'd been stupid. With Tsunade right there, why had he bothered talking so much with this big slug? He could just look through Tsunade's memories about Shikkotsu Forest and settle everything.

By then, Cerberus had stopped. Before it lay a pool of black water. Green mist hung thick over the surface, like a dense web of threads, making the place look bizarre, like a spider's nest.

Nagato controlled Cerberus to lightly touch the black water with its paw. Cerberus immediately barked as its enormous paw sizzled and smoked, corroded by the Black Water.

"Is this the Black Pool, where Shikkotsu Forest's Natural Energy gathers?" After getting the information from Tsunade, the Asura Path continued speaking for Nagato. "Is the way to train in Senjutsu to jump straight in?"

There was disbelief in the Asura Path's voice.

"So you really were reading the information in Lady Tsunade's mind just now!" The slug nodded. "That's right. To put it simply, training in Senjutsu in Shikkotsu Forest is easy: you just enter the Black Water, which contains Natural Energy. But as you've seen, the Black Water contains more than Natural Energy. It also contains the acid in my body. An ordinary person who went in would dissolve and leave no bones behind."

Nagato's mouth twitched. He knew the Black Water had probably accumulated plenty of corpse-fluid from past trainees.

As if it knew what Nagato was thinking, the slug continued, "Black Water is a liquid unique to Shikkotsu Forest. It contains not only Natural Energy and acid, but also the Chakra of creatures that failed to train in the past. Even their Chakra can't escape the Black Water's hold. You know that Chakra comes from physical and spiritual energy, right? The physical energy bound in the Black Water's Chakra is the trainees' liquefied cells, while their spiritual energy is the resentment they left behind. That resentment curses the next trainee, making it harder and harder to learn Senjutsu in Shikkotsu Forest."

"Heh. Can't you absorb this stuff?" The Asura Path wore a completely expressionless face as it said without a hint of a smile, "Wouldn't all that Chakra be a great meal for you?"

"I don't eat people!" the slug answered readily. "Besides, anyone with the courage and strength to enter the Black Pool—whether beast or human—is a potential inheritor of Shikkotsu Forest's Senjutsu, and counts as my disciple! Actually, most of those who enter the Black Pool are beasts with enormous amounts of Chakra. Hardly any weak humans dare to go straight into it. Most of them just think they're clever and try splashing some Black Water on themselves to see what happens. But even so, they still die. The bones you saw along the way were left by people like that."

Nagato couldn't help picturing an ordinary person gathering their courage and trying to splash a little Black Water on themselves. They would be corroded until their whole body was a festering mess, then run back screaming in terror, only to die before they got far from the Black Pool.

Those ordinary people thought that splashing a small amount of Black Water on themselves would be harmless, but the energy in it killed them anyway. Their corpses quickly decayed in the acid mist, leaving only their bones.

Given enough time, even their bones would probably be completely corroded.

"Well? You understand now, right?" the slug asked hopefully. "Give it up. If you really want to learn Senjutsu, you could consider Mount Myoboku or Ryūchi Cave."

In short, just don't come bothering me. The slug could only hope to get Nagato, this walking nuisance, out of there as soon as possible.