Naruto stepped forward, into the inner cage of the sealed space, his movements synchronized with a calm confidence. On the other side of the bars stood Kurama, the Nine-Tailed Fox, its crimson eyes narrowing as it observed him. The two locked eyes—man and beast, or perhaps now, soul and soul.
And strangely… both smiled.
This bizarre feeling—of standing within Kurama's domain while also being Kurama—was still new. Naruto's presence now resided in two places at once. One was the body of Uzumaki Naruto, and the other was the sealed consciousness of the Kyūbi itself, now tethered and merging with his own.
"Time to test the true power of the Nine-Tails," Naruto murmured, clenching his fists. His pupils flashed with intensity, and a grin tugged at his lips.
Kurama's chakra surged, turning into golden, ethereal gas that rushed into Naruto's body. As it fused into him, the massive power compressed and condensed, swirling around him like a living storm.
In an instant, Naruto's form was engulfed in golden light. Intricate black magatama markings appeared across his skin and clothing. A powerful aura erupted from his form—the transformation was unmistakable.
Kurama Chakra Mode—also known as Nine-Tails Chakra Mode—was active.
This was the same form Naruto would eventually use to confront the other Tailed Beasts in the original timeline. A radiant, chakra-cloaked form capable of trading blows with the complete form of Susanoo used by Uchiha Madara.
Naruto could feel it coursing through him. This was raw power—pure, living energy wrapped around his will.
But this time… he wasn't just borrowing it.
He was it.
Letting the transformation settle, Naruto slowly retracted the golden cloak, suppressing the brilliant chakra. His breathing steadied.
"I remember… there's an even stronger form beyond this one." He thought of Kurama Mode Stage 2, Tailed Beast Mode, and eventually the Six Paths Sage Mode granted by Hagoromo Ōtsutsuki. But today, he wanted to test something different—something even this world hadn't seen.
A power of his own making: Heavy Particle Mode.
Naruto channeled his will through Kurama, commanding the beast to clap its hands.
"Condense."
The sealed space trembled. A pulse of raw energy exploded outward.
A high-frequency rumble shook the ground, and the air itself seemed to tear apart. The massive underground chamber, built by Minato's sealing technique, began to crack at the edges.
Jiraiya, outside in the real world, felt the change immediately.
The chakra spike was no longer just volatile—it was catastrophic.
"This chakra… It's already surpassed what we saw when the seventh tail emerged."
He struggled to stay upright, holding his crushed ribs. Blood oozed from between his fingers.
"The Nine-Tails is… breaking the seal. No—tearing it apart!"
He had only tried to loosen a few restrictions on the seal, to help Naruto gain access to more of Kurama's chakra during training. But now it was backfiring in the worst possible way.
"This isn't chakra mastery—it's total loss of control…"
"Minato, Kushina… I'm sorry. If I die here, I'll face you both and take responsibility."
Back in the sealed space, Naruto's transformation evolved again.
Crimson markings spread across his skin—his form now laced with transparent red constructs, resembling high-density energy. Kurama's tails fanned out behind him, but their form was no longer just chakra—they had mass.
Every move carried the aura of collapse and annihilation.
Heavy Particle Mode was a form Naruto had theorized based on energy manipulation principles from his world—something akin to nuclear fusion and fission compressed into spiritual chakra.
And now, it was real.
Cracks tore through the sealed space. The spiritual walls distorted like glass about to shatter.
"This place can't hold me anymore," Naruto muttered.
"Kurama's body is now mine, and this space is just a cage."
With no hesitation, Naruto raised his hand and drove it forward—
Boom!!
His punch struck the spiral-shaped iron gate that marked the center of the seal.
The Four Symbols Seal shattered. A burst of light and energy rippled outward.
In the real world, the ripple manifested as a shockwave of chakra that sent rocks flying and trees splintering.
It would have been impossible to break the seal in the original story without the help of external forces like the Gold and Silver Brothers' chakra or the Truth-Seeking Orbs during Six Paths Sage Mode.
But this time, Naruto's Heavy Particle Mode, fused with Kurama's soul, gave him power the original never had.
Still, there was a price. As Naruto deactivated the form, he felt Kurama's chakra deplete rapidly. The beast's vitality was heavily drained—its regenerative capabilities crippled for now.
"Too risky," he muttered. "This mode is a trump card—only for emergencies."
But even so, the test had been a success.
Suddenly, the air in the broken seal shimmered. Two chakra silhouettes began to form before him.
Naruto narrowed his eyes.
He knew exactly who they were.
Namikaze Minato and Uzumaki Kushina.
In the original timeline, their chakra remnants had been embedded into the seal by Minato, meant to activate only in moments of great distress—like during Naruto's Eight-Tails transformation.
He had gotten so carried away with his experiment, he forgot that this moment would trigger them.
His eyes gleamed with amusement.
He reactivated Nine-Tails Chakra Mode, and two enormous golden chakra claws extended from his back, lashing forward.
Snap!
The claws seized both chakra specters before they had fully formed.
Crack!!
In less than a second, the figures of Minato and Kushina were torn apart.
The seal hadn't stabilized their forms yet. They never had a chance to speak.
Their dissipated chakra floated in the air—two weak orbs.
Naruto drew them in with another set of claws, pulling the energy toward him.
The moment he absorbed them, his eyes widened.
Memories.
Kushina's included fragments of Uzumaki sealing techniques—the chains, the barrier formulas, and a portion of the clan's unique chakra control.
Minato's was even more valuable: complete Rasengan mastery training, the logic behind the Flying Thunder God Technique, and embedded within it, his battlefield intuition as a Kage.
Naruto inhaled.
"This… this is incredible."
He now possessed the combat skills of a Hokage, the unique chakra of an Uzumaki, and the soul of the Nine-Tails itself.
And the world had no idea what was about to emerge from the wilderness.
He stood at the edge of the crumbling seal, eyes flashing gold.
"Time to turn prophecy… into conquest.