Chapter 351 – The Fourth Stage
"Don't you think your conditions were a little too harsh?"
On the road leaving the Land of Fire's capital, Ayaka finally couldn't help but glance at Uchiha Kei.
The naked threat in Kei's words still echoed in her ears.
It wasn't the first time she had seen Kei act forcefully—far from it.
But this kind of dominance, displayed on a political stage, was something else entirely.
It wasn't just strong.
It was unreasonable.
Uncompromising.
That was something Ayaka had never seen before.
And yet, she couldn't deny the results.
The benefits gained from that overwhelming pressure were nothing short of astonishing.
The four "basic conditions" Kei had proposed could only be described as daylight robbery.
They completely stripped the Daimyō of his right to independent protection and, through public narrative alone, subjected him to deliberate and brutal political stigmatization.
Once such an image took hold—whether it was incompetence, poor judgment, or failure to control subordinates—it would become fixed in the minds of the populace.
And that kind of perception was fatal.
Once the people no longer respected the Daimyō, the shinobi certainly wouldn't either.
Over time, the Daimyō would be reduced to nothing more than a symbolic purse-holder—a decorative figure whose only real function was to pay.
That, precisely, was Kei's goal.
And on top of that, he had carved out a massive financial gain.
Not only did he secure a hefty personal reward, he also forced a significant increase in Konoha's annual funding.
The Daimyō's yearly allocation to Konoha was already enormous.
Even though Konoha was capable of self-sufficiency, the Daimyō had always insisted on providing funds—both to assert his "authority" and to maintain the illusion that he stood above the village.
Now Kei had pushed that number up by thirty percent.
That increase alone nearly matched Sunagakure's entire annual budget.
If the Kazekage ever learned that Kei had casually extorted such a sum with little more than words and presence, the jealousy would be unimaginable.
And yet, such conditions were not something anyone could endure.
Even the Fire Daimyō would never have agreed under normal circumstances.
But Kei's most lethal line had come at the very end:
"If you find this excessive, you may send one of your children instead."
That wasn't negotiation.
That was a death threat.
Go yourself—or I'll choose your successor for you.
No matter who lived or died, the order would bear the Daimyō's name.
There was no difference.
That single sentence carried such crushing weight that the Daimyō made his decision on the spot—
He would personally go to Konoha.
"It was fine," Kei said with a faint smile, utterly unconcerned.
"At least we achieved the objective."
"And everything went smoothly," he continued.
"With the rumors spreading, Kakashi escorting the Daimyō back to Konoha for negotiations, and gaining enormous political capital from it—this operation ended perfectly."
Kakashi had been left behind in the capital.
On the surface, it was to let him persuade the remaining guardian shinobi to defect to Konoha—and to keep the Daimyō under watch.
In reality, this entire affair had been engineered to generate momentum for Kakashi.
There was no one better suited to handle it.
Of course, Kei had also left him a private order:
If those men refused to join Konoha—eliminate them.
The Land of Fire had no need for wandering shinobi.
Former Daimyō guards knew far too much, and letting them leave the country would invite unpredictable consequences.
Their options were simple.
Join.
Die.
—or shave their heads and become monks.
Kei didn't even want to give them that third option.
But given how deeply ingrained religious belief was among the civilians, he restrained himself.
In his eyes, faith should mean standing firm in the face of despair.
If you didn't even believe in yourself, why would any god protect you?
"…Your real objective was the Nine-Tails' chakra, wasn't it?"
Ayaka knew Kei too well. She shook her head with a faint smile.
"Honestly, I didn't expect you to use the Three-Tails' chakra for experimentation back then. And now—those chakra fragments… you absorbed them, didn't you?"
"That sharp, huh?" Kei looked genuinely surprised.
"How did you notice?"
"The Nine-Tails' chakra you released in the palace," Ayaka replied calmly.
"I've been around you long enough. And I've studied senjutsu—even if I never truly succeeded, it enhanced my perception."
"I sensed your chakra mixed within the tailed beast chakra."
She paused, then continued.
"And knowing you, there's no reason you'd waste such a thing as evidence."
"The only explanation is that it would've exposed you—so you destroyed it."
She tilted her head slightly.
"By the way… I've discovered your secret. You're not going to silence me, are you?"
Kei stared at her, torn between laughter and disbelief.
When had she become this playful?
If he wanted her dead, she wouldn't still be standing here.
She was far too important—and she knew far too much.
Still, since she wanted to play along, he was happy to indulge her.
"What's the point of saying that now?"
Kei's expression suddenly turned icy.
His eyes bled crimson.
Black chakra surged around him.
"Knowing so many secrets… killing you would certainly put my mind at ease."
"So that's how it is?" Ayaka sighed in mock boredom.
"Looks scary, but there's no killing intent at all. That's not the Uchiha Kei I know when he's serious."
"Is that so?" Kei smiled faintly as the black chakra dissipated.
"Then I suppose my acting still needs work."
"In truth, you're the bored one," he added.
"I was just playing along."
"Should I thank you for that?" Ayaka shook her head, then grew serious.
"But jokes aside—can you tell me why you're collecting tailed beast chakra?"
"What you're doing is extremely dangerous."
She wasn't exaggerating.
Hema's fate had already proven how catastrophic such actions could be.
Now Kei was walking the same path.
She needed to know his intent—to prepare herself, and to prepare countermeasures if necessary.
Even if Kei could handle it alone, another mind meant fewer blind spots.
No matter how capable he was, no one could see everything.
And she, more than anyone else, could see what he might miss.
"There's no need to worry," Kei said calmly.
"Unless I expose myself, no one will ever find out."
"Because that chakra…"
He looked at her directly.
"…is inside my body."
"Inside you?" Ayaka froze.
"You're not planning to become a jinchūriki, are you?"
"If I wanted that," Kei replied flatly,
"I would've fought for it when the Nine-Tails broke free."
Black chakra surfaced once more around him.
"What I need is only the chakra."
"I won't accept a sentient being inside my body—especially one that can observe the outside world through chakra, see everything I do."
"That would make me feel watched."
"Uncomfortable."
"And so—"
As he spoke, the black chakra surging around Kei suddenly exploded outward.
Under his control, Susanoo intensified violently.
In an instant, a half-bodied Susanoo clad in armor manifested around him!
Ayaka stared in a daze at the towering chakra construct before her.
This monster of chakra—
the very power that had allowed Kei to confront the Mist's main forces alone.
Countless Kirigakure shinobi had fallen beneath its hands.
Seeing it from such close range now, the chilling aura felt as though it might swallow her whole.
"That's why I only need the tailed beasts' chakra," Kei said calmly, his voice carrying through the oppressive pressure.
"And it isn't stored inside my body—but within Susanoo itself."
He quietly felt the immense power coursing through the construct.
"At its core, it's all chakra. Susanoo can house tailed beast chakra, and through a process of 'supply,' it can feed that chakra—allowing it to sustain itself continuously. And…"
"And the tailed beast chakra feeds back into Susanoo as well," Ayaka said softly, realization dawning.
"Yes."
Kei nodded, continuing to guide the tailed beast chakra while speaking.
"As I said before, chakra is the essence. Tailed beast chakra can enhance Susanoo itself. Unexpected—but the results are impressive."
As he spoke, Kei suddenly infused the tailed beast chakra directly into Susanoo—
—and his expression changed.
He hadn't expected that simply demonstrating this to Ayaka would spiral into something so bizarre… and so dangerous.
When Susanoo existed without actively layering multiple tailed beast energies, it had been perfectly stable.
But the moment he reinforced it with tailed beast chakra—
The once-solid chakra framework collapsed.
The tightly bound chakra disintegrated, scattering apart.
He couldn't even maintain Susanoo's form!
Kei's face darkened.
"Are you okay?!" Ayaka sensed something was wrong and immediately retreated, shouting.
"Not sure," Kei replied grimly.
"Get farther away. Watch the surroundings. Don't let anyone come close."
"I understand. Be careful."
Ayaka nodded once, casting him a serious look before sprinting off.
Kei ignored her retreat. His thoughts were in chaos.
This situation was of his own making—but that didn't make it any easier to deal with.
He needed to determine whether this collapse was inevitable, or if it was caused specifically by the tailed beast chakra.
If it was the chakra, then why had he never experienced this when using the Three-Tails alone?
Why did the instability only appear when the Three-Tails and Nine-Tails chakra were combined?
"Do they need to be applied one at a time?" he thought.
He shook his head.
"No. No matter how strange it is, tailed beast chakra is still chakra. There shouldn't be incompatibility."
All tailed beasts originated from the same source.
Their conflicts stemmed from will, not chakra.
Future Naruto, future Sasuke—even Obito—all wielded multiple tailed beast chakras simultaneously.
The chaos came from consciousness, not energy.
So the issue wasn't incompatibility.
Then—
Was it his control?
No.
His eyes had already surpassed the Mangekyō threshold.
Suppressing chakra without will should be trivial.
Kei exhaled slowly.
Susanoo—the construct that once fully enveloped and protected him—had nearly disintegrated.
Though chakra still lingered around him, it offered almost no protection.
"This is a serious problem," he muttered.
"If this happens mid-battle every time tailed beast chakra is triggered…"
He stopped.
"…Releasing… re-forming…"
Kei froze.
Third-stage Susanoo and Fourth-stage Susanoo were fundamentally different.
Adding the lower body wasn't just cosmetic—it granted true mobility.
And its scale…
Even an incomplete Fourth Stage dwarfed the previous form.
Not inside the torso—
The user stood atop the head.
"Madara's complete Susanoo caused massive chakra turbulence before stabilizing…"
Kei recalled the scene.
Ōnoki had once said—
'That overwhelming chakra has finally stabilized.'
Why stabilize?
Because it had first collapsed, then restructured.
"So… Susanoo needs more chakra," Kei murmured.
"And it must be restructured and stabilized through my eyes."
The realization crystallized.
His Mangekyō began to rotate as he formed seals.
Nine-Tails chakra had pushed Susanoo beyond its limit—but instead of reinforcing it, it caused collapse.
Now he understood why.
If restructuring was required—
Then he would force evolution.
His consciousness sank inward.
He returned to that familiar inner space—the first place he had ever encountered Susanoo.
Before him stood the colossal black giant, radiating suffocating darkness.
Its crimson eyes mirrored his own.
Kei raised his right hand.
The giant did the same.
When their hands met—
A torrent of chakra surged into him.
So dense.
So overwhelming.
For a moment, it felt beyond control.
But this chakra was his.
It had always been his.
Kei withdrew his consciousness.
When his eyes opened—
An ocean of chakra engulfed him.
Black as ink, cold as death.
Leaves withered.
The ground cracked beneath the pressure.
He inhaled, seals held steady.
His Mangekyō spun faster.
The chakra responded—reassembling.
First a skeleton.
Then meridians.
Then flesh.
Then armor.
Kei halted briefly—this was enough.
But then—
Chakra poured into the lower half.
Bones formed.
Muscle followed.
A crystalline cockpit manifested atop Susanoo's head.
Kei rose into it as the legs solidified.
The construct grew.
Larger.
Taller.
When it reached nearly eighty meters, the growth ceased.
Susanoo trembled—still unstable.
Kei did not stop.
As his Mangekyō slowed, his own chakra erupted.
The giant resonated.
The air screamed.
The roar shook the earth.
Finally—
The vibration ceased.
The colossal giant opened its eyes.
Crimson.
Terrifying.
The Fourth Stage had awakened.