Naruto: Monthly Refreshing Passive System

The combat zone crackled with intense energy, the air thick with tension. As the battle raged on, it became evident that Naruto was no longer just fighting against the combined strength of Madara, Shisui, Kimimaro, and Obito.

He was also battling against the growing darkness within himself, a darkness fed by the power and influence of Otsutsuki Isshiki.

Every strike Naruto delivered carried with it not just his own formidable strength but also the overwhelming power of Isshiki, whose presence loomed over the battlefield like a shadow. His movements were swift, almost too fast for the eye to follow, and each blow landed with the force of a small explosion.

Despite their combined might, Madara and the others found it increasingly difficult to keep up with Naruto's relentless attacks.

Each time they managed to gain an upper hand, Naruto's form would adapt, his powers amplifying with Isshiki's assistance. The once proud and confident Madara found himself being pushed back, his own formidable skills barely enough to parry Naruto's assaults.

"His strength... it's unlike anything we've faced before," Obito muttered, his Sharingan spinning as he tried to anticipate Naruto's next move. "Isshiki's influence is making him stronger by the second."

Shisui nodded, his eyes sharp and focused. "We need to find a way to sever that connection. If we don't, Naruto will continue to grow stronger, and we might not be able to stop him."

Madara, holding his ground with the black staff formed from Yin-Yang Release, could feel the pressure mounting. The sheer force behind Naruto's attacks was beginning to wear him down, even with the power of the giant Rinnegan bolstering his own strength.

"You speak as if it's that simple," Madara grunted, narrowly dodging a blast of black flames that Naruto conjured with a flick of his wrist. "Isshiki isn't just lending him power. He's intertwining their very essences. Separating them might be impossible."

Kimimaro, observing the exchange, remained silent but resolute. His bone-based abilities gave him a unique advantage in this battle, and he knew he had to time his moves precisely. Every opportunity to strike had to be taken with absolute precision.

Naruto, for his part, seemed almost to revel in the chaos. The power surging through him was intoxicating, and Isshiki's voice echoed in his mind, urging him on, feeding his rage and desire for destruction.

"They think they can stop us, Naruto," Isshiki's voice was like a cold whisper, resonating in Naruto's thoughts. "But they are only prolonging the inevitable. Show them the futility of their resistance. Show them our true power."

With a roar that shook the ground, Naruto unleashed a wave of energy, the black markings of the Karma Seal glowing ominously.

His eyes, one still the pale Byakugan and the other the golden dazzle of Isshiki's eye, reflected the inner turmoil and the overwhelming power struggle taking place within him.

Madara felt the shockwave before he saw it, the air around them distorting as Naruto's energy surged outward.

He raised his staff, channeling the power of the Rinnegan to form a barrier, barely managing to deflect the brunt of the attack.

"Naruto!" Madara called out, his voice carrying both a command and a plea. "Can you still hear me? Fight against it! Don't let Isshiki take control!"

But Naruto's response was a cold, mocking laugh, his voice layered with Isshiki's deeper tone. "You're the one who doesn't understand, Madara. This is my destiny. This is the power I was meant to wield!"

As Naruto spoke, the sky above them began to darken, clouds swirling ominously. The atmosphere grew heavier, as if the very fabric of reality was bending to Naruto's will. Lightning crackled across the sky, and the ground trembled beneath their feet.

Kimimaro seized the moment, rushing forward with the speed and agility that made him one of the deadliest fighters in the ninja world.

His hand morphed into a sharp, bone-like spear, aimed directly at Naruto's heart. If he could pierce Naruto with his Kekkei Genkai, perhaps it would be enough to disrupt Isshiki's influence, even if only for a moment.

But just as Kimimaro was about to strike, Naruto vanished, his form flickering like a shadow. He reappeared behind Kimimaro, his hand outstretched, a swirling orb of black energy forming in his palm.

"Too slow," Naruto said coldly, thrusting the orb toward Kimimaro's back.

Time seemed to slow as Kimimaro twisted his body, narrowly avoiding the attack. The orb missed its mark by a hair's breadth, exploding against the ground with a force that sent debris flying in all directions.

Obito took advantage of the distraction, activating his Kamui to warp space around Naruto, attempting to trap him in another dimension. The swirling vortex appeared, threatening to engulf Naruto, but the young ninja merely smirked, his golden eye glowing brighter.

"Kamui? You think that trick will work on me?" Naruto sneered, his voice laced with arrogance. He reached out, his hand glowing with the same black-red energy, and grasped the edge of the vortex.

With a twist of his wrist, he tore the vortex apart, dispersing the Kamui like it was nothing more than a puff of smoke.

Obito's eyes widened in shock. "What… how?"

Naruto's smirk widened, his gaze locking onto Obito. "I told you, this power is beyond anything you can comprehend."

Shisui and Madara regrouped, their eyes meeting briefly as they prepared for another assault. Despite the overwhelming odds, they knew they had to keep fighting. Not just for themselves, but for Naruto, who was still somewhere inside that darkness.

"We need to end this," Shisui said quietly, his voice carrying a note of urgency. "If Isshiki gains full control, we may not get another chance."

Madara nodded, gripping his staff tighter. "Then we fight with everything we have. For Naruto, and for the future of the ninja world."

As they readied themselves to launch another attack, a sudden, powerful pulse of energy radiated from Naruto. His entire body began to glow with a blinding light, and the air around him crackled with electricity.

"Finally," Isshiki's voice echoed through the battlefield, filled with satisfaction. "The time has come."

Madara, Shisui, Kimimaro, and Obito felt a chill run down their spines as they realized what was happening. This wasn't just another power surge. This was Isshiki preparing to take full control, to bring about his own resurrection through Naruto's body.

"We can't let him!" Madara shouted, charging forward with renewed determination. "We have to stop him now, before it's too late!"

The others followed suit, unleashing their most powerful techniques in a desperate bid to halt the transformation. The ground shook as their attacks converged on Naruto, the sheer force of their combined might threatening to tear the battlefield apart.

But as the dust settled, Naruto stood unharmed, a barrier of black energy surrounding him. His eyes glowed with an unearthly light, and the markings of the Karma Seal spread across his body, pulsing with Isshiki's power.

"Too late," Naruto said, his voice a blend of his own and Isshiki's, resonating with dark power. "The resurrection is complete. Otsutsuki Isshiki has returned!"

With those words, a pillar of light shot up from Naruto's body, piercing the heavens and shaking the earth.

The sky above split open, and a malevolent presence descended upon the world.

The final stage of Isshiki's plan was now in motion, and the fate of the ninja world hung in the balance.

(End of Chapter)