Hidan himself was already immortal.
And as a member of the Akatsuki, Senju Haruto naturally showed no mercy—his foot lashed out, sending Hidan flying dozens of meters away.
Kakuzu's eyes widened. Though he had already judged Haruto to be dangerous, the sheer destructive strength he possessed still shocked him to the core. That power was on par with Tsunade's monstrous strength.
But before Kakuzu could regain his composure, Sasuke's attack followed right on its heels. Lightning seemed to crackle in his hand as he charged forward.
Against an ordinary shinobi—even one who could not die—this blow would have inflicted grievous damage.
Boom!
Kakuzu's arm whipped out like a long, black tendril, striking Sasuke square in the chest and swatting him through the air.
"Your timing for a surprise attack wasn't bad," Kakuzu said coldly, his feet digging into the ground as he gave chase. "But you chose the wrong opponent."
He closed in on Sasuke, but his eyes never left Senju Haruto.
From what Kakuzu knew, the shinobi of Konoha were bound tightly by their so-called Will of Fire.
Theirs was a path entirely opposite to that of the blood-soaked shinobi of Kirigakure.
They clung to their bonds with comrades, even to the point of obsession.
If Kakuzu threatened Sasuke's life, Haruto would surely intervene.
Just as he had stepped in to protect Haku.
That kindness… would be his weakness.
All Kakuzu needed to do was feint an attack on Sasuke, then strike Haruto at the critical moment. That would secure victory.
"Hmm?"
But the very next second, Kakuzu frowned deeply.
Haruto remained where he was, utterly still, making no move to help.
"Impossible…"
Did he truly not care whether Sasuke lived or died?
The instant doubt clouded Kakuzu's mind, the roar of thunder burst beside his ear.
"You're looking in the wrong direction. Your opponent… is me!"
Kakuzu snapped his gaze back. His eyes went wide as blue lightning engulfed Sasuke's body.
The Lightning Release Chakra Mode?!
Kakuzu's expression twisted in disbelief.
As one of the shinobi world's living fossils, he had witnessed nearly every secret technique, bloodline ability, and forbidden jutsu that existed.
He knew this technique well—an iconic jutsu of the Raikage, passed down through generations.
But it was never taught outside their line.
How could a brat from Konoha possibly wield such a thing?!
"Hmph."
Seeing Kakuzu falter in his shock, Sasuke seized the moment. His lips curved upward as he twisted mid-air, his right leg sweeping out in a devastating kick.
Boom!
Kakuzu lost balance in midair, slammed into the ground back-first, and skidded across the grassy field.
Sasuke landed heavily but firmly, bracing himself.
This was the fruit of his training under Senju Haruto.
Though only a little more than a week had passed, under Haruto's ruthless guidance he had awakened the Sharingan and grasped the first stage of Lightning Release Chakra Mode.
"Amazing…" Sakura's eyes went wide, sparkling with shock.
She had never imagined Sasuke could send flying an opponent that even Zabuza himself had failed to defeat.
The truth was, despite training under Haruto alongside Sasuke, she had no real measure of how far they had grown.
Only now, in this instant, did Sasuke truly realize the depth of Haruto's strength—and how much stronger he himself had become.
"Well done, Sasuke," Haruto remarked with a nod.
But in the very next breath, he poured cold water on the boy's pride.
"Still far from enough. As a shinobi, you cannot let emotion cloud your judgment. If I hadn't stepped in earlier, you'd already be dead."
"Battle isn't fought that way," Haruto said, his voice low and steady.
He wasn't trying to trample Sasuke's spirit—merely to drive the truth into him.
Sasuke lacked information. He had no idea what Hidan's ability truly was.
But Haruto knew it in exact detail.
If Sasuke had been nicked by Hidan's scythe just moments ago… if his blood had been drawn…
That cursed ritual would have ended him instantly, without hope of resistance.
That was why Haruto had intervened and kicked Hidan away so mercilessly.
In terms of raw power, Hidan was hardly remarkable. Without Kakuzu, he wouldn't even have been able to handle Asuma's team.
Worse, he was the very definition of a reckless hothead.
His fighting style was pure chaos—some might call it "free-spirited," but in truth, it was just wild and undisciplined.
Yet what made him dangerous was not skill.
It was his twisted immortality.
Once he tasted his opponent's blood, the so-called "Curse Ritual of Jashin" would bind their fates together.
Through mutual destruction, he could guarantee victory.
"Damn it…" Hidan spat, his voice a guttural snarl as he dragged himself up.
Normally, because of his immortality and devotion to Jashin, every wound he received only heightened his ecstasy.
But Haruto's strike had been different.
It wasn't just pain.
It was a suffocating agony that ripped through his body, leaving him wishing for death—even though he could not die.
If not for his immortality, his organs would have been pulverized into nothingness.
That man's strength defied reason.
"I've decided, Kakuzu!" Hidan snarled, raising his triple-bladed scythe and pointing it straight at Haruto. "This one's mine!"
"Taking a direct hit from Haruto-sensei's kick…" Sakura whispered, a shiver running down her spine.
That power had been monstrous.
Even solid rock would have been shattered beyond recognition.
By all logic, Hidan should have been killed outright.
And yet here he stood, grinning as if nothing had happened.
"Not only that," Zabuza added grimly. "When I cut him with the Decapitating Greatsword, the wound reached his heart. He should have been finished. But he was still moving, as if untouched."
"And once he draws his ritual circle, any injury he suffers rebounds instantly onto his opponent."
"Senju Haruto…" Zabuza's face darkened. "This man may truly be immortal."
The words struck Sasuke and Sakura like ice water.
If Hidan truly could not die… how could they ever hope to defeat him?
"That headband," Haruto murmured, narrowing his eyes. "He's from Yugakure—the Hidden Hot Water Village. I've heard rumors before… whispers of a so-called immortal."
He nodded once, affirming it.
In this world, such techniques did exist.
"But no jutsu is without weakness."
Haruto's lips curved into a faint, dangerous smile.
"Unfortunately for you, Hidan, the weakness of your so-called immortality… is me."
"What?!" Hidan barked out a harsh laugh. "Me, having a weakness? Don't make me laugh!"
Even as his jeering echoed across the battlefield, new forces arrived in waves—
Kakashi, his body crackling in Lightning Release Chakra Mode.
Naruto, cloaked in the golden glow of his Nine-Tails Chakra Mode.
And behind them, the mercenary samurai forces hired by Gato.
The battlefield was about to erupt in full chaos.