Karma.
This ability isn't limited to attacks launched against Sasuke.
Unlike another Devil Fruit on the sea called the [Karma Karma no Mi], Sasuke's Karma cannot, like the Karma Karma no Mi, transform an enemy's attack 100% into size and strength and then counterattack. (T/N: Karma-Karma Fruit. Since Urouge's Devil Fruit is unknown, but he used Karma-based ability, it'll be named Karma Karma no Mi for now.)
Its 'conversion rate' isn't that high.
But this ability also has its advantages.
That is, the target of its effect isn't limited to actual physical attacks.
Anything that causes Sasuke pain can be considered a 'Calamity', the only difference being the degree.
Whether it's mental attacks or the current counter-damage, all are included.
Feeling the increase in his physical energy, a fierce, battle-ready smile appeared on Sasuke's face.
"Chakra Mode? I can do that too!"
The next moment, crackling lightning enveloped Sasuke's body.
"This is..."
Roshi recognized this familiar state… it was the Lightning Release Chakra Mode from Kumogakure.
Very early on, Naruto had discovered that Sasuke was not only skilled in Fire Attribute Ninjutsu but also had a certain talent for Lightning Attribute.
Therefore, after copying this mode from the Raikage, he immediately taught it to Sasuke.
The Lightning Release Chakra Mode wasn't a particularly difficult Ninjutsu to learn… it relied more on daily, bit-by-bit accumulation.
It's like someone with poor physical fitness, even if they had the Lightning Release Chakra Mode, the amplification wouldn't be strong, and it wouldn't last long.
Thud!
The next moment, Sasuke kicked into the rock wall, instantly causing countless cracks to appear throughout the mountain face.
Both lightning and magma possessed extremely high temperatures.
Gravel fell rustling down, melting upon contact with the high temperature when it landed on Sasuke and Roshi.
At the critical moment, Roshi utilized the Four-Tails' Chakra.
It wasn't just summoning a single tail… he directly cloaked himself in the Tailed Beast Cloak.
Because of this, he barely withstood Sasuke's kick.
"Sea Bottom Needle!"
Roshi wasn't one to just take a beating without fighting back. In his Tailed Beast Mode, the temperature of the magma on his body was even higher.
With his shout, extremely high temperature gathered on his palm, and his entire arm turned red.
The scorching airflow from the high temperature made all the fur on Sasuke's body stand on end.
He wasn't about to be outdone.
Coincidentally, not long ago, Sasuke had also developed a move similar to this one.
Calamity Flames and Lightning Release Chakra quickly intertwined.
Utilizing the [Chidori] taught by Kakashi, and the Calamity Flames from his Huodou transformation…
Plus the enhancement of Lightning Release Chakra Mode covering his body.
Zzzap-
All these powers wrapped around Sasuke's arm.
At this moment, Sasuke's arm was like an indestructible sharp sword… even an unconscious swipe against the mountain wall could split it without hindrance.
This move was named [Lightning Fire Sword], a suggestion provided by Naruto.
It's just that, for some reason, Naruto's expression always looked a bit strange when mentioning the name of this move, like he wanted to laugh but didn't dare. (T/N: The RAW of Lightning Fire Sword can be read as Ken Raika, which is a Director of 'educational Anime'.)
[Sea Bottom Needle] and [Lightning Fire Sword] collided in mid-air.
The convergence of electric light and flames instantly produced a violent explosion.
Boom-
Sasuke was sent flying backward, his entire body covered in burns.
The feedback from Karma nearly doubled his physical attributes in that instant.
But this also meant that Sasuke was genuinely quite seriously injured at this moment.
On the other side, Roshi's figure was also sent flying, crashing heavily to the ground.
Compared to Sasuke, who was rapidly recovering with the infusion of Calamity Flames, Roshi looked much more miserable… the upper half of his body, along with his clothes, was burned badly.
If not for the protection of the Tailed Beast Cloak, that last strike might have been enough to blow his arm off.
"Cough... What an incredible kid. I admit I underestimated you."
Roshi pushed himself off the ground and stood up, his aura also undergoing a change.
This meant he was about to use his ultimate, trump-card technique.
The fighting spirit on Sasuke's body didn't diminish in the slightest… lightning and flames once again transformed into armor.
About a few dozen meters away from the battlefield, Naruto and the group had now gathered.
"Are we really not going to help?" The one who asked this was Yugito, who had only recently joined.
Hearing this, before Naruto could speak, Jiraiya answered first.
"That kid Sasuke wouldn't appreciate your help. After training for so many days, it's good to let him have some real combat practice. After all, his goal isn't any weaker than the Four-Tails' Jinchuriki."
As he spoke, he turned to look at Naruto beside him.
"Besides, Naruto wouldn't let you interfere in their fight, right?"
At this, Naruto showed a big smile.
"Of course! As for Sasuke, he's having fun right now."
...
On the battlefield, with Roshi's battle declaration, even more massive Chakra began to surge from his body.
His body also began to quickly transform from a human shape into a giant ape form.
Complete Tailed Beast Transformation!
This was a power he had successfully mastered after wandering for so many years.
Thud! Thud! Thud! Thud!
The giant red ape landed on all fours… just a light sweep of its four tails could split mountains and crack stones.
Even after entering the Complete Tailed Beast Transformation, Roshi could still maintain his own consciousness and wouldn't fall into an out-of-control rampage.
At this moment, the size ratio between him and Sasuke reversed… it was his turn to look down on the other from above.
"If you have any last words, I can relay them for you."
Roshi certainly understood that Sasuke's strength was remarkable, but that was all.
The Complete Tailed Beast Transformation him and the previous him were two completely different things.
"After I defeat you, I might be willing to listen to yours."
Facing the immense pressure from the Four-Tails, the smile on Sasuke's face grew even wider.
The Mangekyo Sharingan also began to spin under the genuine threat of death.
Although the sense of pressure was still completely incomparable to Naruto's exaggerated level, Sasuke could feel that, due to the death threat posed by the Four-Tails' Jinchuriki, Roshi, a power was beginning to brew and grow within his eyes.
In the distance, sensing the change in Sasuke's aura, Naruto laughed.
"That's it... Transform into a strong warrior before death, Sasuke."
[Lava Release: Flower Fruit Mountain!]
The giant ape pressed its palms against the ground, and immediately, a massive amount of magma turned into a river, completely covering the ground.
Even with Huodou's heat resistance, standing on such ground would cause considerable damage.
Sasuke, self-taught, imitated the water-walking technique, gathering his Armament Haki to the soles of his feet, thus maintaining his stance.
The next moment, Roshi's attack had already arrived.
The giant fist could even cover half of Sasuke's body. In terms of brute force alone, the Four-Tails, Son Goku, could even throw the massive Eight-Tails, Gyūki.
One could imagine the force behind this punch.
Fortunately, Sasuke also knew he couldn't take it head-on. Before the attack arrived, he used his Observation Haki to perceive its trajectory, then his whole body brushed past the fist like a piece of paper.
Then, Sasuke simply dropped to all fours and ran up the Four-Tails' arm.
"Ha!"
A powerful knee strike was blocked by the Four-Tails' tail, preventing it from hitting its head.
The next moment, magma spewed from the Four-Tails' mouth as if it were free, threatening to completely cover Sasuke.
Splash-
After the magma covered it, that figure turned into a puff of smoke and dissipated.
"A clone? No, it's Konoha's Shadow Clone Technique."
By the time Roshi realized something was wrong, Sasuke, who had concealed his presence, had already silently reached behind Roshi using the paw pads of a canine.
[Soru: Silent Step!]
Then, Lightning Attribute Chakra and Calamity Flames gathered once again.
Another Lightning Fire Sword thrust heavily into the Four-Tails' 'tail root'.
Hiss-
Everyone who saw this scene collectively sucked in a breath of hot air.
The others all looked at Naruto, their expressions seeming to ask, "Did you teach him this move too?"
Naruto seemed to understand their meaning and quickly spoke to explain.
"Don't misunderstand! That move is something Sasuke learned from Kakashi-sensei himself. Kakashi-sensei was our previous team's Jonin Instructor."
Upon hearing this, even Jiraiya, who knew Kakashi, showed a strange expression.
'To think that Konoha's Hatake Kakashi was that kind of person.'
At this moment, far away in Konoha, Kakashi, who was flipping through the latest issue of [Icha-Icha Paradise], suddenly sneezed.
"Huh? Is someone talking about me?"
He's completely unaware that his reputation was being unfairly maligned.