The pool before Kaito was no ordinary body of water. It was a passage forged by the power of the Tenseigan, a tunnel between Earth and the moon. The surface shimmered like glass, yet when he extended his senses, it devoured his perception like an endless void.
Taking a steady breath, he stepped forward. His figure vanished into the waters, swallowed whole by the gateway.
When he emerged, the world had changed.
Gray-brown soil stretched endlessly beneath a barren sky. The land was littered with bones, bleached and broken, scattered across a desolate battlefield that reeked of death. Black lines streaked the ground like streams of dried blood, staining the earth in ugly patches.
The oppressive atmosphere sent a chill crawling down his spine. It was as though he had stepped into hell itself.
At the center of the wasteland floated a massive golden sphere. Though fragments of broken pillars surrounded it, none supported its weight anymore—it hung in the air like a miniature sun, radiating pressure that made the air heavy.
Upon its surface, a hexagram pattern pulsed with light. From it emanated a pupil force so overwhelming that Kaito instinctively tightened his fists. The sheer weight of it could crush nations.
The colossal eye was none other than the Tenseigan—the ultimate evolution of the Byakugan.
Kaito's mind raced as he studied it. There were two ways the Tenseigan could be born. One was through the collection of the Ōtsutsuki clan's Byakugan, uniting their bloodline into a single source of power. The other was by transplanting the pure Byakugan of Hamura's descendants, once isolated on the moon, into those of the Hyūga clan on Earth.
This Tenseigan, suspended before him, was clearly the first type—formed from countless Byakugan of the Ōtsutsuki who had lived and died here. It was a crystallization of Hamura's lineage, a power directly connected to his chakra.
Kaito stepped lightly onto one of the broken pillars, his eyes locked on the golden sphere. His heart pounded with anticipation.
If he could draw on its energy, the growth of his own power would surge beyond imagination.
A voice echoed faintly in his mind, urgent and impatient. Take it… swallow it.
He reached out, fingers trembling with restrained excitement. With a flick of his wrist, the ruined pillars around him collapsed into dust. The vast chamber trembled, and he narrowed his eyes. His electromagnetic senses spread outward like a net, probing the moon's depths.
A faint pulse answered him.
Kaito smirked. So, there are still remnants of the moon clan here…
He sensed a lone presence hidden far below, faint but steady. That presence was merging with the Tenseigan, undergoing a process of fusion. Recognition sparked in his mind.
"Ōtsutsuki Toneri…" Kaito muttered. In the original history, Toneri would not fully complete his integration for several years after the Fourth Shinobi War. For now, he was still weak—far from a threat.
Satisfied, Kaito closed his eyes. His chakra shifted, his mental energy opening like a floodgate. Before him, the radiance of the Tenseigan surged like a second sun, spilling waves of pressure across the moon's surface.
He felt it pulling at his mind, tugging at the depths of his spirit. The connection formed instantly.
Streams of energy burst forth from the Tenseigan and poured into him, raw and blazing, like torrents of molten light.
Time became meaningless.
The chakra pouring into him was not gentle. It burned, twisted, and pressed against his very soul. His body felt heavy, but his mind soared as though drifting into a dream.
He saw fleeting images—memories of his old world, long before he arrived in this one. Friends laughing, mistakes he regretted, words he had never spoken aloud. Fragments of a life left behind.
For a moment, he felt the drowsy embrace of nostalgia and slipped into unconsciousness.
But while his body slumbered, his spirit did not.
Within the dark recess of his mindscape, Kaito saw himself—or rather, a spiritual reflection of himself. The figure loomed larger than life, radiating an aura that dwarfed his previous strength.
Around it swirled torrents of energy, compressed and refined, reshaped into something sharper. The spiritual projection of Kaito inhaled the power like a black hole devouring stars. With every pull, his presence grew heavier, more commanding.
Hours passed, though he could not tell how many. When at last his eyes opened again, he found the golden sphere before him dimmed and broken. The Tenseigan had dissolved, its power completely absorbed.
He exhaled slowly, feeling the change within.
Inside his mindscape, his spiritual form stood taller than ever, its silhouette vast and unshakable.
Then, like a whisper, knowledge bloomed in his mind. Memories not his own flowed into him—secrets of Yin Release, the methods to shape illusions not with hand seals but with willpower alone.
His eyes sharpened. "So that's it… using mental energy as the medium."
Closing his eyes, Kaito followed the instructions. He focused, channeling his mental energy directly into his eyes.
A low hum resonated as his vision shifted. His eyes darkened, their depths unfathomable, like black holes that could draw others into endless illusions.
It wasn't a dōjutsu in the traditional sense. Instead, it was the manifestation of his overwhelming mental force, weaponized through his gaze. Stronger than genjutsu cast with hand seals, yet fundamentally similar.
Kaito clenched his fists, conflicted. A part of him had hoped for something more—a bloodline limit like the Uchiha's Sharingan or the Hyūga's Byakugan. Instead, he had gained mastery over pure mental energy.
It wasn't disappointment exactly, but it was close.
Still, he couldn't deny the truth. This power was his now, honed to fit his style. And if wielded well, it could rival any kekkei genkai in the world.
His lips curved faintly. "Good enough. This will do."