BOOM—!
The earth let out a low, thunderous groan.
The ground trembled, like the heartbeat of the planet itself was pounding in agony.
A flash of blinding light tore through the heavens—then came the shockwave. A wave so intense it distorted the very air into visible ripples, smashing everything in its path skyward before reducing it all to shreds.
It radiated outward for dozens of kilometers.
Even Kai and Madara, stationed far from the blast's epicenter, felt the force. Though the power had weakened significantly by the time it reached them, it was still more than enough to rattle the bones.
Had they been even a few kilometers closer—near the very heart of the explosion—there would've been no escape.
Not even for a shinobi.
Not even for Madara.
A direct hit from that kind of attack, with a ninja's typically high offense and low defense, would've meant instant vaporization. Not even Susanoo could guarantee survival at ground zero.
Kai stood quietly, watching the towering mushroom cloud in the distance.
His expression was a blend of awe and solemnity.
It was his first time witnessing a nuclear explosion with his own eyes—and even he hadn't anticipated this level of devastation.
Compared to this, even a Tailed Beast Ball seemed tame. The scale, the intensity… this wasn't just destruction. It was erasure.
Gone in an instant.
And the warhead used? Just a medium-sized Dongfeng Express.
Even now, Kai wasn't sure whether it could overpower the fully charged Tailed Beast Ball from the Nine-Tails—but it was undoubtedly stronger than the standard ones.
Yet raw power wasn't the most terrifying part of nuclear weapons.
It was the aftermath—the silent, invisible death that lingered long after the fire and shockwave were gone.
Nuclear radiation.
It would turn the entire area into a massive death zone, uninhabitable for decades. A place where even the most resilient organisms would wither away. All without a single drop of chakra needed to sustain it.
Anyone who dared return to this scorched land—anyone who dreamed of rebuilding Iwagakure—would face a slow, rotting death.
You stay, you die. You run, you live.
Unless someone in this era somehow deciphered the science behind nuclear fission and radiation shielding, this weapon was practically invincible.
Cruel?
Undoubtedly.
But it was the result Kai wanted.
This wasn't just destruction—it was permanence. A way to erase Iwagakure from the map once and for all.
The [Modern Physical Exchange Voucher] he had used to acquire the Dongfeng Express had turned out to be more potent than he had imagined.
He'd definitely be rethinking how he used those vouchers moving forward.
"How's that? Battlefield clean enough for you?"
Kai spoke with an air of smug confidence, lips curled into a faint smile.
Madara didn't answer immediately.
His eyes were still on the distant inferno, disbelief flickering in them.
"What kind of jutsu is that?" he finally asked. "There's no chakra trace at all."
He sounded less like a warrior and more like a scholar, stunned by something that defied his understanding of the world.
It was like watching a fairytale unfold in reality—like a magical girl appearing out of nowhere and hurling a [Comet Azrael] across the battlefield. It didn't make sense. It wasn't supposed to be possible.
Kai chuckled.
"Nuclear Release: Nuclear Explosion Technique."
Madara narrowed his eyes.
"There's… such a nature transformation?"
Kai shrugged casually. "It's a technique from another world. Ordinary shinobi wouldn't be able to grasp it."
Madara's brows furrowed deeper.
"So I can't learn it either?"
"This technique goes beyond even S-rank. It's not something one person can master. If Konoha kept advancing for another few decades, you might stand a chance."
Madara grunted in understanding, his curiosity still burning—but he didn't press further.
He'd figure it out eventually. He always did.
Maybe this was all just a show of force. A warning.
Kai's unpredictable teleportation and devastating "Nuclear Release" had made him a threat surpassing even Hashirama in Madara's mind.
If this man wanted to, he could erase an entire shinobi village with the press of a button.
What if he attacked in the middle of the night, while Madara slept?
There might not even be time to activate Susanoo.
Damn it, Kai… Don't think for a second I'll let you use this kind of power to force me into submission.
Paranoia crept in, sharpening Madara's wariness.
But even as he gritted his teeth, he asked a pressing question.
"You already had that kind of power… so why involve me in destroying Iwagakure?"
Kai didn't miss a beat.
"Because sages don't interfere in worldly matters. You destroyed the village, not me."
Madara stared at him in disbelief.
You've got to be kidding me.
'You call that not interfering?'
"You were one launch away from blowing it up yourself!"
"And what kind of so-called 'sage' keeps calling himself a sage every five minutes?"
Shameless.
Absolutely despicable.
In Madara's mind, this guy might even be worse than Tobirama.
He didn't say that out loud, of course. His face stayed stoic, unreadable.
Kai, for his part, knew exactly what he was doing.
The real reason he couldn't raze Iwagakure directly wasn't because of some sage doctrine. It was the system's restriction—a rule tied to his existence in this world.
Since Kai wasn't originally from this Naruto world, the world itself instinctively rejected him. The system provided shielding to allow his presence, but if he caused too much direct bloodshed, that rejection would intensify.
And that would jeopardize the main mission: unifying the ninja world.
So Kai had to use pawns—supporting others, like Konoha and Madara—to achieve his goals. His hands needed to stay relatively clean.
That's why he needed Madara.
But if anyone mistook his restraint for weakness?
He wouldn't hesitate to bury them.
Suddenly, Madara flinched.
"…Hmm?"
His eyes narrowed as he glanced at his own skin.
Something felt… off.
There was no visible damage, no injuries—but he could feel it. A subtle, microscopic tearing. His cells were distorting. Weakening.
To anyone else, it would've been undetectable.
But Madara's level of bodily control was on a whole other level. He could sense even the smallest fluctuations in muscle tension, the faintest twitch in his own chakra.
This wasn't chakra-based damage.
This was something else.
"You feel it, don't you?" Kai asked, his voice calm.
Madara's eyes narrowed, a flicker of confusion crossing his stoic face. "What is this? My body… it feels as though I've been exposed to some insidious poison, yet there's no visible wound, no chakra signature."
"Its radiation," Kai explained. "It steadily corrodes the body's strength. Think of it as a massive, unseen barrier—one that doesn't fade. Stay in it long enough, and you'll rot away."
Madara clenched his fists, absorbing the explanation.
"I see. So this is your method of… 'handling' a battlefield."
He let out a slow breath, eyes darkening.
"No one will be rebuilding Iwagakure after this."
"…Hmph."
He looked sideways at Kai.
"You call yourself a God, but you're more like a Demon. Even that bastard Tobirama wasn't this cruel."
Kai laughed, brushing the insult off like dust from his robes.
Cruelty?
He considered himself a good philanthropist.
He'd waited until the village was nearly destroyed before unleashing the Dongfeng Express.
Compared to the bloodbaths started by Madara and Obito during the Third and Fourth Ninja Wars, this was nothing.
"Alright, time to hold up your end of the bargain."
Madara's voice had hardened again.
Kai raised a hand.
"Now's not the right moment."
He could indeed pick a specific point in time and enter a parallel Naruto world—like [World No. 5], where the Fourth Great Ninja War was unfolding.
But once a time node was locked, it became the permanent anchor. The timeline would flow normally after that, meaning future visits couldn't rewind back.
He needed to use that chance wisely.
Better to wait until more allies or spectators were available. Then he could send them all together—for maximum insight, maximum gain.
Madara wasn't having it.
"That's a weak excuse," he said coldly. "And my patience is wearing thin."
Even if he couldn't beat Kai, he wasn't about to be jerked around.
Kai tilted his head, smirking.
"Well, I can take you to other timelines instead."
Madara paused. "Oh?"
Kai nodded.
The unification progress in this Naruto World—[World No. 1]—had just passed 50%. As a result, the system had lifted some restrictions.
He could now take up to two bound members of his faction with him across worlds.
He couldn't take Madara to watch the Fourth Great Ninja War just yet—but he could offer a different kind of tour.
Another world.
Another future.
"Let's go," Kai said.
Before Madara could respond, Kai activated [World Teleport].
And in the blink of an eye—
They were gone from [World No. 1].
Vanished, without a trace.