Chapter 3: The Gallery's Whisper
The rhythm of secrecy had become Kuroto's new normal. His days were a carefully performed play of mediocrity at the academy. His nights, however, belonged to the infinite Gallery and the lonely, resilient dojo on the academy's edge. The encounter with Aizen had lit a fire under him, not of panic, but of cold, focused urgency. He had a key to infinite armories, but he didn't know the weight, balance, or breaking point of most of the weapons inside. That ignorance was a vulnerability he could not afford.
For weeks, his training split into two parallel tracks: further grinding his body and reiryoku reserves in the gravity chamber, and clandestine experiments with Kagami no Sho.
Part 1: The Law of Cost
He started with Jishin no Tsuchi, his Earth of Steadfast Weight. It was his baseline, his control sample. Night after night, he practiced summoning it, holding it, and using its gravity field. He mapped the drain on his spirit with the precision of a scientist. At its steady state, he could maintain the Shikai for just under two hours before nearing critical depletion. Actively using its power to increase local gravity in a small area spiked the cost exponentially. He learned that the "reflection" was not a perfect 1:1 replica of the original weapon's power in its native world; it was filtered through his soul, his understanding, and the spiritual mechanics of this reality. A power based on a fundamental force like gravity was relatively efficient. The Staff of Ainz Ooal Gown, by contrast, was an alien invocation that his soul struggled to parse, hence the catastrophic cost.
This led to his first major hypothesis: The more a reflected weapon's power and origin deviated from the spiritual-energy-based system of the Soul Society, the greater the cost to wield it. It was a law of metaphysical friction.
Part 2: Echoes of Other Worlds
With this theory in mind, he ventured deeper into the Gallery, seeking specific, clamorous whispers he had long ignored. He needed data points. He stood before a mirror that seethed with a silent, anti-magical rage. The reflection showed a version of himself, muscles coiled, wielding a gigantic, rough-hewn broadsward that was more a slab of dark metal than a blade. The essence was Negation. Not destruction, but a void. An absolute cancelation of spiritual and magical phenomena. The whisper was a constant, grating sound of shattering chains and stifled screams. This was the Demon-Slayer Sword, the Anti-Magic weapon of Asta.
He focused, pouring his reiryoku into the Prism. "Kagami no Sho."
The summoning was violent. The air didn't shatter; it screamed. A wave of null-pressure exploded outwards, silencing the ambient reishi in the dojo for a moment. The sword that formed in his hands was immense, five feet of dull, black iron. It felt unnaturally light for its size, but holding it made his own spiritual energy churn uncomfortably, as if repelled by its very nature.
He didn't even attempt a command. Merely holding the reflection was agony. It was like gripping a live electrode made of pure void. His reiryoku didn't just drain; it was eaten, consumed at a rate that made the Staff of Ainz feel economical. In less than ten seconds, his knees buckled. The black sword dissolved into fragments of oppressive shadow before vanishing, leaving him gasping on the floor, his spiritual pressure flickering like a dying candle.
Hypothesis confirmed, he thought, shuddering. The Anti-Magic sword was a conceptual anathema to a being made of and powered by spirit energy. Wielding it was an act of self-immolation. A weapon of absolute last resort, if it could be used at all without killing him first.
After a day of recovery, he tried another. This mirror shimmered with predatory elegance. The reflection held a sleek, imperial armguard. Its essence was Adaptation and Camouflage. The power to absorb the traits of a defeated foe and transform. The whisper was the sound of shifting scales and silent footsteps. Incursio, the Teigu from Akame ga Kill.
"Kagami no Sho."
The summoning was smoother, quieter. The object that appeared was not a weapon, but a single, beautifully crafted gauntlet of dark blue metal covering his left forearm. It felt cool and alive, humming with latent potential. The drain was significant, but less than the Anti-Magic sword—it was a tool of physical enhancement and transformation, concepts closer to home.
He focused, trying to will it to activate, to draw out its power. The gauntlet thrummed, and he felt a pull, a hunger. It wasn't asking for his reiryoku; it was asking for data, for a biological or spiritual template to copy. It had none. In this state, it was just a very sturdy piece of armor. To use its true power, he would need to defeat something powerful and let Incursio "consume" its essence—a dangerous and morally fraught prospect. He released the reflection, the cost incurred for a dormant Teigu still being notably high.
Part 3: The Search for Synergy
The experiments were exhausting but illuminating. He began to categorize the reflections:
· High-Synergy, Low Cost: Like Jishin no Tsuchi. Powers based on physical laws or elemental forces native to spiritual realms.
· High-Synergy, High Cost: Potential powerhouse Shinigami-style Zanpakutō from his gallery he hadn't yet met in reality. Their cost was high due to raw power, not conceptual friction.
· Low-Synergy, Catastrophic Cost: Like the Anti-Magic Sword or the Staff of Ainz. Alien systems. Tools of last resort.
· Conditional Tools: Like Incursio. Powerful, but requiring external components to function.
He needed more in the first category. He spent hours wandering the Gallery, not seeking the loudest shouts, but the most harmonious hums. He found a few: a sword that could generate and control pure, solid light (a moderate cost, useful for constructs and barriers). A dagger that induced a paralyzing numbness on contact (low cost, subtle). A bow that fired spiritual energy arrows that never missed their mark (high cost per shot, but efficient).
He practiced cycling through them quickly in the dojo: Light Blade to parry an imagined strike, switch to Gravity Sword to anchor and counter, switch to Paralyzing Dagger for a finishing touch. The mental and spiritual strain of rapid "refraction" was immense, but it was a skill he had to master. Kagami no Sho was not meant for prolonged duels with a single weapon; its true potential was in bewildering, unpredictable adaptability.
Part 4: The Unwitting Instructor
It was during one of these rapid-refraction drills that he sensed it again—that placid, deep-water pressure at the edge of his perception. He immediately froze, letting all reflections shatter, holding only his plain Asauchi. He turned, expecting to see Aizen in the doorway.
The dojo was empty.
But on the dusty floor, just inside the entrance, lay a single, slim volume. It was not an academy textbook. The title was handwritten in elegant, precise strokes: "On the Resonant Properties of Reiryoku and Conceptual Manifestation."
Kuroto approached it slowly, as if it were a trapped Hollow. He picked it up. The pages were filled with dense, theoretical discourse on how spiritual energy could interact with abstract concepts—time, space, gravity, negation. It was far beyond sixth-year curriculum. It was, he realized with a chill, tailored research. Aizen wasn't just watching. He was guiding the experiment, providing intellectual fodder to see how his unique subject would digest it.
The message was twofold: I see your struggles with conceptual friction. Here is a lens to understand it. And more ominously: Your progress interests me. Accelerate it.
Kuroto closed the book, his knuckles white. He was no longer just a curious anomaly. He was Aizen's personal laboratory rat, being given mazes to run and puzzles to solve. The freedom to experiment felt suddenly like a gilded cage.
He looked at his Asauchi, the unassuming Mirror of Many Scribes. The Gallery within felt both like a treasure and a trap. He had tested its echoes, learned its costs, and categorized its reflections. But now, his research had a demanding, invisible overseer.
The foundational testing phase was over. He had a roster of potential reflections, understood their prices, and had his body pushed to a higher threshold. The theory was solidifying. The next step, he knew, wouldn't be in the silent dojo. It would be in the live-fire exercise of the real world. He needed a real template, a real fight, and a way to use his kaleidoscope of stolen powers without his patron-scientist understanding the full extent of what he could truly reflect.
He pocketed Aizen's book. It was a dangerous gift, but knowledge was power, even from the devil. He would read it. He would learn from it. And he would use it to build a cage of his own, one reflection at a time.