Uchiha Kai opened his eyes, and the world before him gradually shifted from a blur to clarity. The light was dim, the air damp and cool. The stone walls around him were rough and uneven, naturally shaped into elliptical curves. It was clear—he was in a cave.
Taking a deep breath, Kai exhaled slowly. Though his body ached with fatigue, a wave of relief washed over him.
He had finally completed that hellish mission and made it safely back to the outskirts of Konoha's territory.
Reaching up to rub his left eye, Kai winced. It was still swollen, though his vision hadn't been affected. Still, the pain reminded him of the cost.
He couldn't help but think—if even a few uses brought him this much pain, how had Uchiha Madara managed to fight Senju Hashirama for days before awakening the Eternal Mangekyō Sharingan?
Unlike Uchiha Sasuke, who had rapidly adapted to his Mangekyō through intense battle and calculated guidance—courtesy of Uchiha Obito—Kai didn't have such support. He couldn't afford to use his ocular powers recklessly.
Still, he had to admit: Sasuke's rapid growth was astounding. His progress with Susanoo alone had been terrifyingly fast.
"These moments of calm... they bring me peace," Kai thought, as the tension in his eye began to subside and he lowered his hand. The cave was crude and uncomfortable, but it was safe—and that was more than enough.
This was, without a doubt, the most peaceful moment he'd had in half a month since joining the front lines of the Third Shinobi World War.
It was hard to believe that just yesterday, he'd been locked in vicious combat with Iwa-nin.
In that battle, he had used the power of his left Mangekyō eye: Leap of Time, a technique that accelerated his own time flow, making him move at speeds incomprehensible to his enemies. With it, Kai had eliminated four Iwa-nin with almost surgical efficiency.
While he appeared to move faster than normal, the truth was more complex. His own temporal perception and physical time had accelerated, while the world around him remained unchanged. It wasn't true teleportation—his body still needed to move physically, chakra still burned, and his eyes bore the brunt.
Kai had learned to restrain the technique. Pushing the acceleration too far would cause immense strain—muscles tearing, chakra depletion, and worst of all, rapid loss of ocular power.
Even with cautious use, his eyes now throbbed with fatigue, and his chakra reserves were running dangerously low.
"The Akimichi clan's stimulant pill must've worn off... and all the accumulated fatigue from this campaign is finally hitting me at once," Kai thought, trying to shift position. Pain exploded through his limbs. His entire body felt like it had been crushed.
Those four Iwa-nin had been formidable—especially as a team. Without his Mangekyō, Kai would've had to retreat, relying on tactical evasion. The Three Tomoe Sharingan simply wouldn't have been enough.
Thankfully, that wasn't the case anymore.
Though his Mangekyō came with a price, Kai was adapting. More importantly, every battle was teaching him something new about his abilities. This time, Leap of Time had given him insights into its strategic potential—especially when paired with his other Mangekyō technique: Retrospect of Time, a power that allowed him to rewind the actions of others within a short window.
"If I can apply Leap of Time to a kunai the moment I throw it... it would be nearly impossible to dodge. A real surprise attack," Kai mused.
"And if I'm ambushed... a quick activation of Retrospect of Time could reverse the moment and give me an edge. More efficient. Less exhausting."
In the world of shinobi, conserving strength was crucial. One never knew what the next mission—or enemy—would bring. Efficiency could be the difference between survival and death.
Holding a target in a time loop for extended periods consumed far more chakra and pupil power than simply affecting them for an instant. Strategy was everything.
Kai had learned that lesson the hard way. If he faced those four Iwa-nin again, he would not be caught off guard.
His thoughts were interrupted by the sound of approaching footsteps echoing through the cavern. Instinctively, Kai reached for a kunai and focused on the cave entrance.
But then he smiled wryly.
"This is what battlefield trauma does to you..." he muttered. "Jumping at every sound."
Still, he didn't think that was a bad thing. Constant vigilance was part of being a ninja—during war, and in peace.
"Kai-kun, you're awake?" a familiar voice called. Namikaze Minato stepped into the cave, his usual warm smile on his face. Seeing Kai lower his weapon, Minato chuckled. "No need to be on edge—we're safe. You look like you finally got some rest."
"Captain Minato." Kai nodded and relaxed, slipping the kunai back into his pouch. "Still sore, but it's manageable. Though I doubt I'll be any help in a fight right now."
"You won't need to fight anymore," Minato said gently as he took a seat nearby. "Orders just came in. Kai-kun, you're being sent back to the village."
"Back to Konoha?" Kai blinked in mild surprise, but it wasn't entirely unexpected.
He had awakened the Mangekyō Sharingan. That alone would draw the attention of both the Uchiha clan and the Hokage's advisors.
During wartime, the village and the Uchiha often maintained a tense but quiet truce. Neither side dared to push too far. The village couldn't afford to antagonize the Uchiha, and the Uchiha couldn't risk rebellion—not yet.
A shinobi like Kai, bearing the Mangekyō, wouldn't be left in the field much longer. The village would want him watched. The clan would want him protected.
Even if it meant pulling him from the front.
Taking a slow breath, Kai nodded. Truthfully, he was relieved. He needed time—time to recover, to reflect, and most importantly, to better understand his new powers.
His kaleidoscope of time—both forward and back—had only just begun to open.