Orochimaru was once again on the back foot, desperate and cornered. The Sannin's remaining heads hissed, the colossal white snake preparing to burn every last drop of its chakra to mount a full-power counterattack.
But inside the seal, the Great Fox was already laughing.
"You should have just started at six tails, brat," Kurama's voice rumbled through Naruto's mindscape, a dark, bloodthirsty hum.
'Yeah, right,' Naruto mentally shot back, focusing on the seal's limits. 'You know that with this current seal, six tails is my absolute limit without losing my mind. If I hold that state for more than ten minutes, my body won't be able to handle the physical strain afterward.'
"Ah, don't be a coward. You can handle it. Rip him apart."
In the physical world, the air pressure in the crater violently imploded.
A sixth tail of boiling, corrosive red chakra erupted from the base of Naruto's spine. But the transformation didn't stop at the chakra cloak. A horrifying, dense white substance began to manifest over the boiling red energy. Thick, skeletal bone armor formed over his forearms and legs, while a terrifying, hollow skull-like mask materialized over his face.
"So..." Naruto spoke, his voice now entirely distorted by the bone mask, sounding like two demons speaking in perfect, terrifying unison. "You're not going to die that easily, huh? Then I guess I have to try something else."
Before the syllables even finished echoing, Naruto vanished. He didn't use Body Flicker; his raw physical speed simply broke the sound barrier.
He reappeared directly above the massive white snake. With a single, brutal swipe of his bone-plated arm, Naruto slashed through one of Orochimaru's two remaining heads, violently ripping it clean off its neck.
Orochimaru shrieked in absolute agony, a horrific, gurgling sound that shook the earth. The final, central head lunged forward, snapping its massive fangs at the boy. Naruto didn't even flinch. He whipped one of his six tails forward, batting the massive snout aside with enough force to shatter its jaw, before driving a bone-crushing right hook into the side of the snake's skull, sending the colossal beast crashing backward.
Realizing the surface was a death trap, Orochimaru frantically dug his massive body underground, violently tunneling into the bedrock to escape the onslaught.
"There is nowhere to hide," Naruto growled.
He landed at the edge of the massive sinkhole Orochimaru had just dug. Inhaling sharply, Naruto condensed a massive amount of fire-natured chakra mixed with the Kyuubi's raw power in his lungs. He unleashed a devastating, white-hot Firestorm directly down into the tunnel. The flames roared through the subterranean passageway, turning the earth into molten glass.
A second later, the ground fifty yards away exploded. Orochimaru erupted from the earth, heavily burned and desperate. The colossal snake whipped its massive, scaled tail in a final, blind attempt to crush the boy.
The heavy tail slammed directly into Naruto, crashing him into the bedrock. But the boy didn't stay down. He dug his bone-plated claws directly into the scales of the tail, securing a death grip.
With a roar of exertion, the miniature, six-tailed beast spun on his heel. Utilizing sheer, impossible physical strength, Naruto lifted the thousands of tons of the great white snake off the ground, spun it through the air by its tail, and hurled it across the crater.
As the great snake crashed into the opposite rock wall, Naruto leaped high into the smoke-filled sky. He opened his jaws, and once again, the blue and red chakra particles violently condensed. This Tailed Beast Bomb was smaller, but infinitely more unstable and powerful than the last.
He fired it with the velocity of a sniper bullet.
Down below, the trapped and battered Orochimaru saw the black sphere descending. In a final act of desperation, he whipped his remaining, ruined stump of a head upward to intercept the blast. The resulting explosion instantly vaporized the secondary head, burying Orochimaru's main body beneath thousands of tons of collapsed rock.
Naruto plummeted from the sky like a meteor. He didn't use a jutsu. He simply focused every ounce of the Nine-Tails' physical strength into his right fist.
He landed squarely on the buried Sannin's back. CRACK. Naruto's fist punched clean through Orochimaru's thick white scales, shattering his spine, and driving a massive hole entirely through the Sannin's chest cavity.
Orochimaru's final, central head let out a blood-curdling scream of pure, unfiltered agony. The head weakly raised itself from the rubble, opening its jaws to fire one last, desperate blast of energy at the boy standing on its back.
Naruto simply opened his mouth and unleashed another concentrated Firestorm at point-blank range, entirely engulfing the head in unquenchable flames.
"I told you," Naruto rumbled coldly, keeping his hand firmly buried inside Orochimaru's chest cavity. "I am not leaving you alive."
Naruto unleashed a massive, hyper-concentrated pulse of the Kyuubi's most corrosive, toxic chakra directly into Orochimaru's internal organs. The red chakra acted like an aggressive acid. Orochimaru screamed one final time as a blinding white light erupted from his core. The corrosive energy completely burned away his cellular structure from the inside out.
When the light faded, there was no body left. Only a massive, smoking pile of grey ash.
Naruto bounded backward, landing heavily on a stable piece of bedrock.
Immediately, the violent, boiling red chakra began to recede. The bone armor cracked and dissolved into the air, and the six tails melted away. Naruto's actual body was revealed, his skin heavily blistered and burned from the sheer toxicity of his own cloak.
His legs gave out. Naruto fell back onto his butt, catching himself with his hands as he heaved, gasping desperately for air. The strain on his chakra coils was agonizing, but already, the residual Kyuubi chakra was emitting a soft steam, rapidly healing the burns across his face and arms.
'Kurama...' Naruto panted mentally, his vision swimming slightly. 'Can you sense him anymore?'
"Not a single trace, brat," the Fox replied, sounding thoroughly satisfied. "Not in this area. His chakra signature is completely extinguished."
"Well..." Naruto muttered aloud, wiping sweat from his forehead. "Finally... the snake went down."
A sharp rustling sound from the crater's edge made Naruto snap his head up.
Standing a few dozen yards away was Team Kakashi.
Sakura had both hands clamped over her mouth, her eyes wide with absolute, paralyzing horror as she took in the apocalyptic wasteland before them. Sai was beside her, his usual, unbothered fake smile completely gone, replaced by genuine, wide-eyed shock at the sheer scale of the destruction.
Yamato stood in front of them, heavily on guard. His hands were locked in a firm hand seal, his Wood Style chakra already thrumming in his veins, ready to restrain Naruto if the boy showed even a hint of losing control.
Kakashi, however, immediately bypassed Yamato and quickly bounded down into the crater, landing at his student's side.
"Naruto," Kakashi said, his Sharingan scanning the boy for fatal injuries before looking out at the smoking pile of ash. "Where is Orochimaru?"
"In ashes," Naruto breathed out, managing a weak smirk. "Had to go to six tails to beat that guy completely. But I'll admit... if he wasn't already weakened from his failing body, and if I hadn't been training my ass off for three years... I wouldn't have been able to destroy him."
"He was one of the Legendary Sannin for a reason," Kakashi agreed quietly, a profound sense of relief washing over him.
Yamato slowly approached, his hands still tense.
Naruto looked up at his temporary captain and waved a tired, dismissive hand. "You can lower your Wood Style down, Yamato. I'm not going to go Kyuubi mode again. I'm in control... Ouch!" Naruto winced, grabbing his shoulder as a sharp muscle spasm hit him. "Man, the blowback from using that form is really something bad."
Kakashi quickly stepped to Naruto's left side, wrapping the boy's arm over his own shoulders and lifting him to his feet with steady support.
"Kabuto has been successfully captured and sealed," Kakashi reported softly, making sure Naruto was stable. "And Orochimaru is dead. So, Captain... what's our next move?"
Naruto leaned heavily against his sensei, taking a deep breath of the smoke-filled air. He looked toward the treeline, his eyes hardening with resolve.
"Now," Naruto ordered, his voice tired but iron-clad. "We take a half-hour rest to let my body patch itself up. And then... we go raid Orochimaru's base."