After Minato Namikaze received the Akimichi clan's potent recovery medicine, he sensed his chakra beginning to replenish. But as clarity returned, he noticed something odd—Uchiha Kai had left behind only a shadow clone and disappeared.
From Uchiha Fugaku, he learned that Hinata Aya had spotted the mysterious black-cloaked figure again. That name instantly tensed Minato's nerves.
He knew that man.
Having fought him before, Minato recognized the signature of Kamui, a space-time ninjutsu far more elusive than his own Flying Thunder God. If not for his superior reflexes and spatial mastery, he might have been slain that night.
But then, a strange relief washed over him.
Reports from Hiashi and Hizashi, the twin Hyuga clan heads, indicated that there might be more than one black-clad assailant—the one who tore through their Byakugan-guarded patrols seemed to possess brute strength more than space-time ninjutsu.
"This second one… might be even more dangerous," Minato muttered. "And if Kei-kun runs into both at once…"
But he let the thought pass.
"I trust Kai-kun," he said aloud. "He's prepared."
Minato focused instead on what lay ahead. His chakra still had not fully returned—unlike the Uzumaki or Senju, his reserves were finite, and he'd used too much in his battle with Uchiha Obito, who had summoned the Nine-Tails to destroy the village.
He exhaled slowly. "No time to dwell on the side effects."
With a flash of yellow light, Minato vanished, reappearing at his home.
Inside, Uzumaki Kushina lay weak, her life force barely hanging on. As a former jinchūriki of Kurama, she had suffered grievous injuries when the beast was ripped from her.
"Kushina," Minato whispered, gathering her and baby Naruto into his arms. "You have to hold on. I'll explain everything once this is over."
"Minato…" she murmured, as Naruto began to cry.
Minato turned to two waiting figures—Uchiha Fugaku, now holding his Mangekyō Sharingan open, and Uchiha Kai's shadow clone.
"Let's go," he said.
The five of them—Minato, Kushina, Naruto, Fugaku, and Kai's clone—teleported behind the Nine-Tails, near an ancient tree where the ground trembled with the beast's rage.
Even Fugaku, battle-hardened and cold, felt tension seeing the fully-formed Nine-Tails roar. But he composed himself quickly.
"I'll try to restrain him," Fugaku said calmly. "But I haven't fully mastered these eyes yet…"
"We'll support you," Minato nodded.
Kai's shadow clone added, "Even as a clone, I can still help. I'll use Susanoo at partial capacity."
Kushina, barely conscious, glanced weakly at the towering Uchiha chakra avatars and her husband, confused—but she trusted them.
Fugaku stepped forward. His Mangekyō Sharingan spun, the tomoe shifting into a unique pattern of interlocked triangles. The Nine-Tails turned toward him, recognizing that same oppressive gaze it had once seen in Uchiha Madara.
The beast roared and lunged.
But just as its claw would've crushed Fugaku—
A jet-black Susanoo arm erupted between them, catching the claw with thunderous force.
Fugaku blinked. Beside him stood Kai's shadow clone, bathed in a dark skeletal Susanoo.
"You can use this without a real Mangekyō?" Fugaku asked, surprised.
"I'm full of surprises," the clone said. "But I can't hold it long—do your part!"
Fugaku nodded and focused his chakra. His Mangekyō's genjutsu flared—not a full control like Madara's, but a high-level manipulation of the Nine-Tails' chakra-based consciousness.
The tailed beast stumbled. It clutched its head, growling in confusion, as the Sharingan influence bore into its mind.
At the same time, Kai's Susanoo tightened its grip.
The Nine-Tails began to convulse under the dual pressure of Susanoo's physical suppression and Fugaku's spiritual genjutsu.
The clone began to fade slightly, its chakra flickering.
"This won't last," Kai's clone said, teeth clenched. "Do it now, Clan Head!"
Fugaku pushed his Mangekyō to the limit. A blood tear rolled down his cheek as the pupil pattern etched itself into the beast's own glowing eyes.
The Nine-Tails howled—and suddenly fell still.
Its eyes now reflected the same triangular Mangekyō pattern as Fugaku's.
"It's done," he said, panting. "Minato, now!"
Without delay, Minato dashed forward with Kushina and Naruto in his arms.
Kushina raised a trembling hand. Adamantine Sealing Chains burst from her body, wrapping around the beast with golden radiance.
In the manga, Kushina could barely restrain Kurama while dying. But here, aided by the Uchiha duo, her sealing chains locked Kurama like iron shackles.
With both spiritual suppression and physical sealing in place, Minato wasted no time.
"We'll divide it," Minato said, forming hand seals. "One part in Naruto. One part sealed again with Kushina. The third, I'll seal in myself."
Fugaku and Kai's clone stood guard as Minato began the Dead Demon Consuming Seal—the same forbidden jutsu once used by the Uzumaki to seal massive forces.
...
Meanwhile, miles away, Uchiha Kai ran through the forest, with Hinata Aya and Imai Kenta close behind.
He had left some of his Mangekyō chakra in the clone—it was draining, but necessary.
"You said these white cells came from him?" Kenta asked.
"Yes. They're from his partner. The black-and-white guy."
"Sounds like Zetsu," Aya muttered. "But... how strong is he?"
"Too strong to underestimate," Kai replied. "But I've trained. My Susanoo's matured, and my eyes... they've regained power."
Unlike others, Kai's Mangekyō didn't deplete permanently. It slowly regenerated—a mutation he still didn't fully understand.
But it wasn't an Eternal Mangekyō. Not yet.
"I'll handle Obito," Kai said. "You two find Zetsu. Interrupt if needed."
"Understood," Aya nodded. "Oh, by the way... I named your sword."
Kai raised an eyebrow. "Yeah?"
"Kiritama. 'Cutting Soul.'"
"...Sounds like something out of a drama. But fine."
He smirked and vanished into the shadows, donning an ANBU mask.
Before him stood Uchiha Obito, waiting, as if expecting him.
Kai drew his sword, and blue lightning chakra surged across its edge.
"So... the runaway becomes the mastermind," Kai said. "You should've died that day, Obito."
"You say that like you could've done it," Obito scoffed. "Still talking big, Kai?"
"No," Kai said, eyes narrowing. "Just stating facts."
Their blades clashed.
Kai's lightning-charged sword stabbed forward, but Obito vanished into his Kamui dimension.
A black chain erupted from his sleeve, wrapping around Kai. But it wasn't the real one—it was a substitution.
"Boring tricks," Obito said.
"Wasn't trying to win," Kai replied. "Just warming up."
Blue lightning surged again. Kai darted forward with Chidori-speed. Obito activated Kamui—but not fast enough.
The edge of the blade grazed him.
Not a fatal wound—but it proved one thing.
Uchiha Kai had closed the gap.
"You've improved," Obito said coldly.
Kai grinned beneath his mask.
"This time, I'm not here to talk."