Injecting an excessive amount of chakra into a single part of the body, even with Naruto's physical constitution, inevitably led to chakra leakage. The vegetation in the courtyard even began to move as if stirred by an unseen wind.
"Hiss..."
Feeling the excruciating pain emanating from his arm, Naruto couldn't help but suck in a sharp breath. If you pump too much water into a balloon, it will burst. For Naruto now, the chakra pathways in his right arm were the balloon, and the massive amount of chakra was the water. The pain of his expanding pathways far exceeded any superficial injury. He could have bone fragments removed from his body without anesthesia and not even flinch. One could only imagine how terrifying the pain of tearing chakra pathways truly was.
But this agony wasn't for nothing. On his right arm, a current of the White Snake Sage's senjutsu chakra slowly surfaced. After several breaths, when his pathways were on the verge of tearing completely and the pain reached its peak, the final link between the White Snake Sage's senjutsu chakra and him was finally severed.
Thud!
Naruto lay on the ground, pale-faced, his chest heaving like a bellows as he gasped for air.
"Hm?"
Meanwhile, in Ryuchi Cave, the White Snake Sage, reclining on her stone bed, opened her eyes in puzzlement.
"Is something wrong, Matriarch?" Ichikishimahime, attending by her side, inquired.
"...It's nothing." The White Snake Sage shook her head slightly, a trace of doubt flickering in her eyes.
Who made a move? Gamamaru? Or that fellow from the Pure Land? She had left a little something with the harbinger of change, hoping to gain some benefit from the upcoming upheaval. But now it seemed those two wouldn't allow any outsiders to interfere... True enough. A plan a thousand years in the making... if it were her, she wouldn't permit outside interference either...
"You okay?" Kurama asked.
"I'm fine." Naruto pushed himself up, letting out a soft breath.
"Without that old hag's senjutsu chakra, can you still sense natural energy?" Kurama, seeing the matter resolved, slowly lay back down.
"That was just a transitional aid, not a necessity." Naruto sat cross-legged, forming a strange hand seal and holding it in front of his Dantian. "With it, the process of absorbing natural energy is a bit easier. Without it, it just takes a little more time."
In fact, the posture Naruto now assumed was superfluous, and the hand seal was merely a habit he'd developed in Ryuchi Cave. This posture helped him enter a meditative state more easily, to better sense and draw in natural energy. If he truly focused, he could enter Sage Mode even while standing; it would just take longer.
Several minutes later.
A black circle slowly coalesced in the palm of Naruto's right hand. Then, with the circle as its center, black markings began to snake their way up his arm. Finally, these black markings stopped at his right shoulder blade.
The unique perspective of Sage Mode emerged in his mind. Naruto opened his eyes and stared at the markings on his arm, a look of slight astonishment on his face. As if remembering something, he quickly went into the room, stood before a full-length mirror, and slowly removed the open-chested kimono he wore on his upper body.
Gazing at the black markings on his right arm, Naruto clenched his fist. He felt no discomfort; in fact, Sage Mode in this state felt even smoother than when he used it in Ryuchi Cave. And on his face, the purple pigmentation and serpent-like pupils from Ryuchi Cave's Sage Mode were gone.
This was his own Sage Mode.
As for why the characteristic Sage Mode patterns appeared on his arm, it was probably because he instinctively absorbed natural energy through his right arm...
"When Hashirama Senju entered Sage Mode, his face markings were also black," Kurama commented, having naturally noticed the change in Naruto's patterns. "Only, his were on his face. Yours... probably can't be called 'face' markings anymore."
"The markings are just an external manifestation. Where they appear doesn't matter, as long as Sage Mode is still powerful," Naruto said casually, examining his right arm. Compared to having his face gaudily painted, this style of 'markings' better suited his reserved personality.
"Kurama."
"Hm?"
"Lend me some chakra."
Kurama: "..."
Naruto's body was instantly enveloped in a golden chakra cloak. Seeing the black markings still present on his arm, he felt a sense of relief. Just as he had suspected, Sage Mode and Kurama Chakra Mode weren't mutually exclusive. After all, the principle of Sage Mode was to absorb external natural energy to reshape and strengthen the chakra within the body. The chakra that constituted Kurama Chakra Mode was also composed of physical and spiritual energy and could similarly combine with natural energy. Kurama's chakra itself was already of a much higher quality than human chakra. Now, with the added boost from natural energy...
Feeling the immense power within him, Naruto paused in thought for a moment, then vanished from the spot. His rapidly increasing strength had made him a little overconfident. He needed to find someone to take him down a peg...
Amegakure.
Drip, drip, drip!
Due to being constantly shrouded in rain, the people of this village wore raincoats wherever they went. Because no one could guarantee that if they went out shopping on a clear day, they wouldn't return looking like a drowned rat.
Thwip!
A uniquely styled kunai flew from an unknown direction and embedded itself precisely into a building.
"Which brat is carelessly throwing kunai around?" a sharp-eyed Ame ninja who noticed the scene yelled. This was a marketplace with heavy foot traffic! What if someone got hurt?
"Yuryo, wait a second." His companion suddenly grabbed his arm. "I think... I might know who threw that kunai..."
"Who is it?" Yuryo asked, turning his head to look at his companion.
His companion didn't speak, instead pointing gently towards the building ahead. On the wall perpendicular to the ground, a figure of a man in an open-chested kimono had appeared at some point. The man stood on the wall, defying common sense, and slowly bent down to pull the kunai from where it was embedded.
The crowd below watched this scene, murmuring amongst themselves. "Who is this guy? So arrogant?" "Must be from another village, with that style of dress." "The Enforcers are here, let's go, don't want to get caught in the crossfire." "..."
Watching the Ame ninja leaping across rooftops towards him, Naruto paid them no mind. With a light jump, he landed on the tallest nearby building. Gazing at the central tower of Amegakure, he knew Nagato was inside. The chakra-infused rain was the best proof. Rain Tiger at Will Technique—a super wide-range sensory ninjutsu that involved infusing one's chakra into the rain to detect enemies. During the Dragon Vein incident, Nagato had described the concept to him.
"Intruder, what is your purpose in Amegakure?" The Ame Ninja Enforcement Squad surrounded him, demanding harshly. The squad leader, seeing the intruder had no intention of answering, made a few discreet hand signals to his teammates.
Just as they were about to attack, the intruder suddenly turned his head to look at the leader. Instantly, their gazes met.
Ugh...
The squad leader's body stiffened. Fear, originating from the depths of his heart, spread throughout his entire being. Why? He merely glanced at me, and I've lost the ability to move? I can't budge?
Damn it!
Move, damn you!
He roared hysterically in his mind!