As the strongest member of the Uchiha clan in a millennium, Madara Uchiha, before obtaining the Rinnegan, was only second in talent to Indra Ōtsutsuki, who developed hand seals and ninjutsu.
Just like Hashirama Senju, none of the reincarnations of Indra throughout history could surpass him, not even Sasuke Uchiha.
After obtaining the Rinnegan, Madara even surpassed Indra Ōtsutsuki, becoming the most exceptional existence.
After all, neither Asura Ōtsutsuki nor Indra Ōtsutsuki had ever achieved the fusion of the two poles. The so-called Sage Body and Sage Eyes were merely incomplete forms.
Now, Madara had reached the high-level Six Paths stage, second only to top-tier beings like Kaguya Ōtsutsuki and Hagoromo Ōtsutsuki.
Given enough time, with his talent, Madara could fully become the second Hagoromo Ōtsutsuki by mastering the Kekkei Mōra and Yin-Yang Release inherent in being a Ten-Tails Jinchūriki.
In the entire shinobi world, aside from the ultimate secrets of the Divine Tree and the Ōtsutsuki clan from outer space, there was nothing Madara didn't know.
Similarly, the transplantation of ocular techniques within the Uchiha clan was no secret to him.
Yagyu's Outer Path Maru reminded Madara of Obito Uchiha's Mangekyō Sharingan's exclusive technique, Kamui.
With just absorption, it could replicate. Madara didn't know when Yagyu had absorbed his Limbo shadow, but he was certain that this absorption was highly advanced.
Because the Limbo shadow didn't die and couldn't die.
This meant that Yagyu's exclusive technique could even absorb Limbo shadows hidden in another dimension, and it only needed to absorb a little or even just touch it to replicate it.
If that were the case, then if Yagyu obtained the Mangekyō Sharingan, wouldn't he easily complete the transplantation of ocular techniques?
Although Madara looked down on Obito Uchiha, treating him as nothing more than a tool, he had to admit that Obito's eyes were excellent, even surpassing his own Sharingan.
If it weren't for the curse mark he left on Obito's heart and his absolute overwhelming strength, Madara wouldn't have been so confident and composed when facing Obito.
After all, no one understood and detested space-time abilities more than Madara.
Back then, it was Tobirama Senju who used such an ability to kill his brother.
If Yagyu obtained an ocular technique that could hide his true body in another dimension, it would likely be very troublesome to deal with.
Yagyu, of course, didn't know Madara's thoughts.
If he had, he would have once again marveled at how Madara, who couldn't be defeated by the protagonist group and had to be nerfed through dimensional reduction, was more like the final boss than Kaguya Ōtsutsuki.
If it weren't for being a transmigrator, unless he possessed the Rinnegan, Yagyu wouldn't have been able to discern the abilities of Limbo: Border Jail at a glance.
But Madara, after just one look at the purple beam, not only guessed the general abilities of the Outer Path Maru but also instantly thought of Obito Uchiha's corpse and the Uchiha clan's ocular technique transplantation.
Seeing Madara block the purple beam, Yagyu raised his hand, and a large number of black light points surged from his palm.
Seeing this, although Madara didn't know what Yagyu was trying to do, he instinctively spat out a purple beam, attempting to interrupt Yagyu's spellcasting: "Sage Art: Storm Release Light Fang!"
Though both were lasers, this one far surpassed the purple beam Yagyu had returned to him, containing cutting and destructive power far beyond that of the Water Severing Wave, shooting toward Yagyu.
Even a single Truth-Seeking Ball's defense would be pierced, even severed by this laser.
After all, in the original story, this technique had cut through the black rods formed by Naruto's Truth-Seeking Balls.
However, although the laser's speed was fast, Yagyu's spellcasting speed was even faster.
The black light points had already numbered in the tens of thousands, rapidly forming a pure black longsword, much like the formation of a Truth-Seeking Ball.
The nature of this sword wasn't the seven nature transformations of the Truth-Seeking Ball but an upgraded version of the Yin-Yang Release Black Rods, or rather, another application of the Yin-Yang Release Black Rods.
The ability of the Yin-Yang Release Black Rods was similar to the Hyūga clan's Gentle Fist, capable of sealing the flow of chakra in the human body.
Once the Yin-Yang Release Black Rods were inserted into the body, the flow of chakra would be sealed, making it either impossible to use ninjutsu or drastically increasing the difficulty of casting it.
If all key pressure points were struck by the black rods, one's chakra would be completely immobilized, leaving only taijutsu usable.
To some extent, the Yin-Yang Release Black Rods were also a formidable technique, as long as one had chakra, they could create these physical weapons.
Nagato and the Six Paths of Pain particularly liked to use the Yin-Yang Release Black Rods in combat.
However, although the Yin-Yang Release Black Rods were good, their toughness was quite ordinary.
Sharp weapons could cut through the black rods, and if one mastered Sage Mode, they could directly ignore the attacks of the Yin-Yang Release Black Rods.
Even Madara only used the Yin-Yang Release Black Rods during the Edo Tensei period and after regaining one eye.
After becoming the Ten-Tails Jinchūriki, possessing the Six Paths Staff and Truth-Seeking Balls, which were far superior to the Yin-Yang Release Black Rods, Madara looked down on the most basic application of Yin-Yang Release.
Thus, upon seeing this black longsword with the same nature as the Yin-Yang Release Black Rods, Madara, who was spitting out a laser, had a slightly puzzled look in his eyes.
What was this brat doing?
In the next moment, Madara's expression changed slightly.
He saw Yagyu holding the black sword, which even sharp weapons could cut through, colliding with the laser that could sever the Truth-Seeking Ball black rods.
Then, an incredible scene unfolded!
Something was severed, but it wasn't the fragile black sword; it was the small yet infinitely powerful laser.
An invisible force split the tiny laser capable of cutting through anything into two, quickly following the laser toward Madara.
Madara, who had reached the high-level Six Paths stage, actually felt a sense of threat and instinctively stopped casting Sage Art: Storm Release Light Fang, flying sideways to avoid it.
Only after putting several meters of distance between them did the threatening aura disappear.
Madara turned to look at Yagyu, incredulously asking, "What did you just do? What is that sword of yours?!"
Two questions in a row showed just how surprised Madara was.
Madara was absolutely certain that if he hadn't dodged in time, even with his immunity to ninjutsu, he would have been injured.
Although he had an immortal body and would heal even if injured, his combat instincts honed over the years made him instinctively dodge.
This was also why Obito Uchiha and Kaguya Ōtsutsuki were far inferior to Madara.
When one becomes reliant on an immortal body, if the enemy's attack contains hidden tricks, it's easy to be caught off guard.
Kaguya Ōtsutsuki was the best example.
First, she was sealed by her rebellious sons, Hagoromo and Hamura Ōtsutsuki, and then sealed again by the reincarnations of her two grandsons.
The so-called Ancestor of Chakra suffered two humiliating defeats.
Yagyu didn't answer Madara, as if he hadn't heard his words, his gaze fixed on the black longsword in his hand, his eyes filled with surprise and contemplation, murmuring to himself, "Is this the power of will and spirit? Truly... an indescribable power!"
Indeed, the black longsword in Yagyu's hand was the Sage of Six Paths' Divine Sword—the Sword of Nunoboko.
The appearance of Yagyu's Sword of Nunoboko was different from Obito Uchiha's in the original story.
Because the Sword of Nunoboko was both a weapon and a profound application of Yin-Yang Release, more precisely, a secret technique developed using Yin-Yang Release—the Spear of Heaven.
Since it was a technique and created using Yin-Yang Release, Yagyu could shape the Sword of Nunoboko into any form he desired.
He could even turn the Sword of Nunoboko into a knife or an axe, transforming the Divine Sword into a Divine Knife or Divine Axe.
Using the Sword of Nunoboko for the first time, Yagyu found that the level of this technique was somewhat low.
If colored light spheres truly existed beyond three colors, then the three-color level was simply unworthy of the Sword of Nunoboko.
The Sword of Nunoboko, like Obito Uchiha's Kamui, belonged to a transcendent level.
The reason was simple: this technique could utilize the ninth attribute of power!
As everyone knew, chakra had seven attributes: Yin, Yang, and the Five Elements.
The eighth attribute, space-time, was outside the Yin-Yang and Five Elements, and only a few geniuses among mortals could comprehend it.
Space-time was the strongest power Yagyu knew, as space distortion and space tearing could cut through anything.
And space movement was the fastest speed in the world.
Aside from time, Yagyu couldn't imagine any ability that could rival space.
But now, Yagyu seemed to have discovered a power that could rival space-time.
It was the ninth attribute, likely mastered by only one person in the shinobi world—the power of the mind.
The power of the mind, or willpower.
How powerful materialized will could be was evident from Madara's earlier dodge.
It was an invisible force, just like Limbo: Border Jail, that couldn't be seen but was immensely powerful, capable of injuring even a Ten-Tails Jinchūriki.
In addition to natural energy, physical attacks, Six Paths Sage Arts, space-time, and sealing, there was now another force that could harm a Ten-Tails Jinchūriki.
But this wasn't the key reason for Yagyu's surprise and contemplation.
Nor was it the main reason Yagyu felt the game system had underestimated the Sword of Nunoboko!
The real reason Yagyu considered the Sword of Nunoboko transcendent was a sudden flash of insight.
He seemed to understand why the Sage of Six Paths could freely travel between the worlds of the living and the dead.
And why his Edo Tensei could summon spirits from the world of the dead without a sacrifice, and why he could summon Team 7, the nine tailed beasts, and even Madara Uchiha from another dimension without a medium.
The power of the mind? No, it should be... Yin-Yang Release!
What was underestimated wasn't the Sword of Nunoboko, but the Yin-Yang Release, one of the basic abilities inherent in the Rinnegan.
Both Yagyu and Madara, even Kaguya Ōtsutsuki and the Ōtsutsuki clan from outer space, had vastly underestimated the power of Yin-Yang Release.
This technique, which could create everything from nothing and give life to all things, might truly be the most powerful force.
"Yin Release represents the spirit, Yang Release represents the body, I see... I see..."
Yagyu murmured to himself again.
Yin Release chakra was a special chakra secreted by the brain, containing spiritual power.
Spirit, thought, mind, even the soul... all belonged to Yin Release!
Yin-Yang Release wasn't just a technique to create all things; it was also a technique to control the body and soul, develop potential, and harness all energy!
This might be why the Sage of Six Paths, even without being a Ten-Tails Jinchūriki, could become the will of the world and a top-tier Six Paths existence!
At this moment, Yagyu seemed to have realized something.
The Sword of Nunoboko might not be strong, but it was a key that allowed Yagyu to master Yin Release to the level of will and spirit.
Thus, Yagyu, holding the Sword of Nunoboko, flew toward Madara.
Seeing Yagyu, who hadn't answered but instead seemed to be in a daze before flying toward him, Madara, unable to understand what ability he had just used, also flew forward with the Six Paths Staff in hand.
The earlier dodge was just an instinctive reaction.
Now, coming back to his senses, Madara realized he had an immortal body. Even if he suffered great damage, as long as he wasn't instantly killed, he would be fine.
After all, the Ten-Tails, which had reclaimed the chakra of the nine tailed beasts, contained an immense amount of chakra, vast as the sea was an understatement; it was nearly infinite.
Unless he suffered continuous damage beyond his limits, the Ten-Tails wouldn't break free, and Madara could endlessly consume Ten-Tails chakra to heal his injuries.
Moreover, the Ten-Tails Jinchūriki came with so many innate abilities; Madara didn't believe Yagyu could do anything to him with that strange method.
As long as they fought and he understood Yagyu's strength level, Madara had plenty of ways to kill him.
As for whether Yagyu's strength could surpass his own?
Madara didn't even consider such a possibility.
After all, the root of all ninjutsu was chakra, and chakra came from the Divine Tree, which was the Ten-Tails.
Now that the Ten-Tails had become his power, his chakra was like the sun, while Yagyu's chakra was merely the light of a firefly.
No matter how strange Yagyu's methods were, when his chakra ran out, it would be his time to die.
Yagyu and Madara flew toward each other, one from the left, the other from the right.
One swung a sword, the other a staff.
Both were pure black weapons, one merely a creation of Yin Release, while the other contained the power of Yin-Yang and the Five Elements, capable of destroying all creation upon detonation. The difference between them was like heaven and earth, a dimensional gap.
Yet, when the two collided, an incredible scene unfolded.
Crack—rip!
There was no sound of metal clashing and sparks flying, nor was there a scene of mutual force pushing against each other.
Only a crisp sound of something breaking was heard, followed by the sound of cloth tearing.
Madara's Six Paths Staff and his body were cut in half at the waist.