Five minutes later, the incredibly fast Shin and Tsunade arrived at the foot of a mountain and began heading toward its summit. Before long, they caught sight of the enormous body of a slug.
"Is that Katsuyu?" Shin asked in shock, staring at the massive body, over three hundred meters tall even while lying down.
"No, that's only a part of Katsuyu," Tsunade explained. "That portion merely carries her main consciousness. No one has ever seen her complete form, so no one knows how big she truly is."
"Uh..." While Shin was still in awe, he shot Tsunade a somewhat strange glance.
Katsuyu was a sage, on par with the White Snake Sage and Gamamaru. Creatures like Manda and Gamabunta? They weren't even worthy of being compared to her.
Even one-tenth of Katsuyu should have been enough to completely crush Manda and Gamabunta, but in reality, it had shown no particularly impressive performance. That truly did not live up to the name of "sage."
So it turned out it was just a small fraction of a small part, now it all made sense.
Thankfully, he knew Katsuyu was gentle, otherwise, its mountain-sized form alone would be enough to scare him to death.
After a long climb, Shin finally breathed a sigh of relief. The higher they went, the thinner the corrosive gas became. By the time the two reached the mountaintop, the air was nearly indistinguishable from the outside world.
"Hello, Shin," Katsuyu spoke first in a soft, sticky voice, with no arrogance at all. "Do you wish to learn Sage Mode?"
"Hello, Katsuyu. Can I really learn it?" Shin perked up at Katsuyu's initiative, who didn't answer, instead, she swallowed Shin in one gulp.
Shin remained calm. After entering her body, he felt as though he had stepped into another dimension. The next moment, countless streams of natural energy surged toward his body, washing over him like a flowing river.
He closed his eyes and carefully felt the energy, then, to his amazement, discovered that the natural energy was incredibly compatible with him. Almost instinctively, he guided a wisp of natural energy into his body.
As he balanced his physical energy, spiritual energy, and that wisp of natural energy, a trace of senjutsu chakra was generated within his body. Although it was just a tiny amount, everything felt completely natural.
This was his own innate talent, not something inherited from Tobirama. That realization thrilled him, he hadn't even known he possessed such potential.
After spitting him back out, Katsuyu nodded in satisfaction and said, "I can feel that you have a high affinity for Sage Mode. You're well-suited to learning the Sage Mode of Shikkotsu Forest."
"What?!" Tsunade was visibly frustrated after hearing Katsuyu's assessment, deeply frustrated. After all, she had absolutely zero sage talent. It had always been one of her greatest regrets.
She hadn't been too upset about it before.
After all, Shikkotsu Forest's Sage Mode were the hardest to learn among the Three Great Sage Lands, and as far as she knew, only her grandfather had successfully learned them.
But now Shin could learn them too?
Why him?
Still, her complaints were half-hearted, deep down, she was genuinely happy. After all, she had been the one to ask Katsuyu to teach him Sage Mode in the first place, of course she wasn't truly jealous. Right now, all she could think about was helping him gain enough power to protect himself, so he would no longer face the threat of death.
Now that he was learning Sage Mode, it meant he would truly have the power to defend himself, and soon, he'd be able to live openly and safely in Konoha.
Her grandfahter's experience had taught her that when someone was powerful enough, they were no longer bound by the rules.
People like that were usually the ones who created the rules that others had to follow.
When Shin reached the point where he could create rules, would anyone in Konoha still mess with him?
And so, after seven years of frustration, Shin finally began his path of training. Naturally, the one who volunteered to be his teacher was Tsunade herself.
For the next month, every night, he would be reverse-summoned to Shikkotsu Forest.
The way he and Tsunade entered Shikkotsu Forest was through Tsunade summoning a small slug, which would notify the main Katsuyu to reverse-summon both of them.
The method of leaving Shikkotsu Forest was the same as what Naruto used during his battle with the Six Paths of Pain, leaving behind a clone at Mount Myōboku, and having that clone summon him back via summoning scroll when the time came.
So both of them left clones at home, and after a certain time, those clones would summon them back.
During this month, Shin listened to Tsunade explain various ninjutsu principles and combat experience while also learning her Chakra Enhanced Strength.
At the same time, he constantly tested and refined the jutsu he already knew, and trained in the Sage Mode of Shikkotsu Forest. His life was intensely productive.
---
On the peak of a mountain in Shikkotsu Forest, Shin rapidly retreated, dodging Tsunade's attacks as his hands formed seals with lightning speed.
Snake → Ram → Monkey → Boar → Horse → Tiger!
Fire Release: Great Fireball Technique!
The six hand seals were completed almost instantly, his movements too fast to be seen clearly. As Shin took a deep breath, his chest puffed out dramatically while he continued flying backward, as if he were about to suck in all the air around him.
During this process, his chakra surged violently, and an enormous amount of fire element gathered in his throat.
The next second, a massive burst of flames shot from his mouth, rapidly forming a huge fireball that flew straight toward Tsunade.
Wherever the fireball passed, the air warped from the heat, accompanied by crackling explosive sounds.
Just as the jutsu was unleashed, Tsunade, already anticipating the attack, stomped her right foot hard into the ground, causing it to crack and send large chunks of stone into the air.
As the fireball approached, a surge of blue chakra gathered around her right foot. With immense force, she kicked the largest floating boulder. Surprisingly, the rock didn't shatter as one might expect. Instead, propelled by the explosive force of her kick, it shot toward the fireball like a missile.
Using the recoil from the kick, Tsunade landed swiftly.
But the instant her feet touched the ground, she barely tapped it with chakra-coated toes, and her body launched like a cannonball, chasing after the rock.
What shocked even more was that the ground beneath her showed no signs of damage.
Chakra Enhanced Strength: Ultra Precision Mode.
This was a version of the technique that she developed herself, inspired by her granduncle and grandfather, after being driven to improve by Shin's progress. It was essentially an advanced, hyper-controlled evolution of her original power.
Unlike before, when every move caused massive collateral damage, now, in Ultra Precision Mode, she could channel her energy with surgical precision, losing almost none of it to excess force. She had complete control.
Because of the intense concentration of power, her movement speed in this mode was terrifying, basically Body Flicker Technique: Plus Ultra.
In this state, she combined blistering speed, devastating instantaneous power, overwhelming destruction, and elite-level regeneration all at once.
Fancy jutsu? Not important to her anymore.
All of this happened in just a brief moment.
From the outside, it looked like the massive boulder was plowing through the flames ahead, with Tsunade closely following behind it, barely dodging the searing blaze.