Reliquary of Power

During the days Silas was back in Karakura Town, he considered something important. It was that if he had traveled back in time, wouldn't he have chosen to secure the Hōgyoku in the past?

Silas knew himself better than anyone. What he needed was the Hōgyoku. It was the only thing that could help him rival strong opponents like Genryūsai Yamamoto. Assuming he succeeded in acquiring it in the past, wouldn't that mean it was no longer available in the present?

Silas descended to Kisuke's laboratory. It was well hidden amidst thick trees and vines. Judging from the exterior, it clearly hadn't been touched in years.

Silas stopped by the front entrance and gently placed his fingertips on the door. On contact, his spiritual pressure pulsed all around the laboratory, scanning for anyone and anything inside. Deeming that it was safe to enter, he unlocked the hinges and casually walked in.

Vines and moss covered the walls, indicating that this area hadn't been used in ages. Echoing sounds of his steps could be heard as he traversed a narrow hallway. When he stopped by a door, he opened it and found a light switch on the side. Flicking it on and off, he found that the electricity here still worked.

This was good. Very good!

In the original story, after Kisuke's exile from the Soul Society, he sought to destroy the Hōgyoku. This proved impossible for him, so he did the one thing that furthered Bleach's plot: he put it inside Rukia Kuchiki's Soul without her knowledge.

In the story, Kisuke sought to conceal the Hōgyoku forever by giving Rukia a special Gigai designed to gradually transform her soul into that of an ordinary woman. His plan was thwarted when Aizen betrayed the Soul Society to reclaim the artifact.

For some time, Aizen meticulously studied Kisuke's work in the underground assembly hall known as the "Great Archive". It was written to have been used as a repository of all the knowledge and history within the Soul Society and is also an area restricted even amongst some of the captains.

There, Aizen unveiled two methods for extracting an object from a Soul. The first involved obliterating the host soul with intense heat, achievable with tools like the Sōkyoku. Since the Sōkyoku was reserved for severe offenses, he had to orchestrate Rukia's execution.

This scheme was derailed when Jūshirō Ukitake and Shunsui Kyōraku destroyed the Sōkyoku, forcing Aizen to implement the second method. Employing a device of Kisuke's own creation, Aizen successfully removed the Hōgyoku from Rukia's soul.

Silas didn't need to research the Great Archive. He was the Great Archive!

As long as he can locate the blueprints for the device Kisuke created and Aizen used, he could just as easily construct one himself and then extract the Hōgyoku from the premature Rukia.

Without making haste, he set off to do just that.

Kisuke's laboratory wasn't very impressive. Compared to the laboratories in squad twelve, this one paled in comparison. The rooms here were only a little spacious, and the air was thick with the scent of disuse.

Sunlight blazed through the dusty skylight, casting stark beams that cut through the gloom of the abandoned area. In the room, there was a cocktail of mildew and machine oil scattered across the ground.

Glass tubes filled with swirling liquids snaked along the chipped tile walls, some glowing with an eerie inner light. Half-finished contraptions, their purposes defying comprehension, occupied most of the floor space.

Silas wove through the clutter. He sifted through the papers, fingers brushing against faded diagrams and cryptic notes. When he couldn't find anything on the desks, he saw a flash of metal beneath a dusty tarp. It was a workbench littered with scrolls and loose diagrams.

Silas's breath hitched. This might be it.

Fingers skimmed over faded schematics and annotations. A scroll bearing an intricate wax seal made him pause. He unfurled it, his eyes widening as he recognized neat rows of calligraphy—a list of forbidden kidō spells, each holding immense power.

A tempting distraction, but for now, his focus remained on the Hōgyoku.

He placed the scroll aside, his gaze snagging on a worn leather-bound book nestled amongst the clutter. Embossed on the cover was a three-dimensional octagonal shape.

His pulse quickened as he recognized the blueprints.

Schematic diagrams filled the pages, meticulously detailing the device he was looking for. It closely resembled the one depicted in the story: small and metallic, serving as an energy conduit. The name Kisuke had given it was called a "Soul Reliquary" device.

At the back of the book was a materials list. Each component, though undoubtedly rare, was obtainable—soul steel from the depths of the precipice world, a shard of kyokuryu essence, and a focusing lens imbued with spirit particles from the Seireitei itself.

Silas traced the blueprint with a reverent finger. This wasn't just possible; it was within reach.

A worthwhile time to give a wry smile, but he knew better than to get overly excited. Room for mistakes couldn't be made. So he carefully tucked the book inside his cloak, the weight of it a promise of what was to come.

Deciding to scavenge around the laboratory to see if he could find more useful notes or needed materials, his efforts hadn't produced much. The other rooms carried morbid skeleton figures, tarnished sheets of metal, or half-assembled machines. Perhaps he could disassemble them for parts, but now was not the time.

Only after entering a hidden closet did he discover something worth using. Under a mountain of yellowed scrolls was a black cloak. He recognized this cloak, so he swept aside the debris and pulled it out.

This remarkable cloak was designed by Kisuke to suppress his spiritual pressure. It proved indispensable when he stealthily observed Aizen during the Hollowfication of the soon-to-be Visored and again when he approached Ichigo inconspicuously. Moreover, this specialized garment grants safe passage through the precipice world.

Aizen himself had demonstrated a further enhancement to this ingenious invention. By skillfully weaving Kidō into the cloak's fabric, the wearer could blend seamlessly with the surrounding atmosphere, attaining near-total invisibility.

Although there were some torn pieces of fabric, Silas knew he could easily sew them back together. And now that one of them was in his possession, there was nothing stopping him from obtaining the Hōgyoku!