Of all the things Silas had in mind, it was time—time to enact much of his plans. What he understood after reviewing the recent events taking place within the Seireitei was that he had six years before his present self would defeat Aizen again.
But Silas had never been one for idle waiting.
While in the laboratory, he had been skimming through a pile of unfinished work. Many of Kisuke's torn notes were scattered across them. And what Silas found was something worth his attention: an unfinished device capable of tracking a Soul's whereabouts.
Like most of Kisuke's crude inventions, this one had a title on it, "Soul Tracker." It was designed to attach itself to the outside of the Soul and be able to pinpoint that specific Soul's spiritual signatures. Considering these were unfinished notes, Kisuke likely abandoned the project before his exile.
An idea sparked in Silas's mind. A tracker would do more than satisfy his innate goals. So he began crafting it.
The first attempt was a disaster.
The device, spitting sparks instead of fully turning on, sputtered and died. This was because it was cobbled together from half-understood schematics and scavenged materials within the laboratory. Silas remained calm as he normally did, knowing that these were only minor setbacks caused by crude materials.
That became his new focus: find better parts.
Nights spent lurking on the periphery of the Seireitei transformed into daring raids. The only area within the Seireitei that always contained what he sought was squad twelve. Their security was lacking against his cloak, which made him virtually invisible.
"I've been trying to make this awesome invention that I'm sure captain Kurotsuchi would love to know about," a scientist within squad twelve announced to his peers.
"Tell us more about it."
"You see, it's a device that could look far into the sky and see into the Soul Palace. I call it a Soul-Scope!"
The others laughed at him, knowing it would be immediately shut down. Anything that dealt with obstructing matters that took place in the Soul Palace was deemed hazardous.
"Come on, guys!" the scientist begged. "It's a really great idea."
Silas was standing right in the room, his back leaned against the wall and his arms crossed. Was the cloak that powerful? No, but Enrakyōten's copying abilities of Kyōka Suigetsu were!
Silas casually walked out of the room, opening the door without anyone seeing or hearing him. The door itself remained closed to their hypnotized senses. Walking to that scientist's department, he saw the unfinished telescope he was crafting.
As great an idea as this was, the scientist's peers were correct: it wouldn't be approved. And perhaps Silas could use it for his own plans; he would need to know how the machine functioned as well as have all of the blueprints.
He skimmed through the notes and deemed them not worth his time. Even if this Soul Reaper finished the project, it wouldn't work. The materials needed didn't correlate with one another in the slightest.
Silas instead took what he came here for: sekkiseki and shintenken thread. The former was a rare material found only in special ores scattered across the Soul Society, while the latter were wires formed with spirit particles.
After taking the necessary components, he returned to his rundown laboratory to try constructing the device again.
The components laid before him like a meticulously arranged surgical kit. His fingers carefully weaved wires through and pieced the metals together. Weeks became a blur of research, trying to ensure things wouldn't fail again.
He was not Kisuke, a brilliant inventor driven by curiosity, but he was Silas Wren, a man who had honed his skills by adapting to any situation that came his way. As long as he focused on his singular goal, he could always triumph over what was in front of him.
Finally, it was time. After the last connection was secured, he pressed a button. There was no dramatic explosion, no blinding rays. Just a faint light emanating within the device.
Success.
He lifted it, being roughly the size of a fist. Although large for a tracking device, its casing was a patchwork of materials, with practicality overriding aesthetics. It might not win any awards for craftsmanship, but for Silas, it would help with what they needed it for.
The first test was a simple one: himself. He activated the device and placed it on his abdomen. It pulsed in response, then emitted a steady beep, increasing in frequency.
It was tracking him, perfectly attuned to his unique resonance.
And there was something special about this Soul Tracker. Because Silas had infused his own immense spiritual pressure on it, only he would know where and what it was tracking.
He verified this by attempting to sense the device's location. While the link was apparent, the test was subjective. What he needed was to see how far it could track.
Silas removed the device and placed it aside with contentment. The device was interesting in its own rights, but it wouldn't provide the immediate answers he desired. At least for now.
His gaze drifted across the cluttered workbench, finally settling on the unassuming scroll nestled amongst the salvaged tools. It was the same scroll that had instructions and incantations for forbidden kidō spells the Soul Society deemed too dangerous for use.
This was what Silas went on to dabble in next.
He reached for the scroll and unfurled it, revealing dense columns of archaic script and arcane diagrams. Out of the forbidden spells, only a few were truly advantageous for his purposes. Those that caught his attention were the "World-Tying Rite" and "Bakudō #79. Kuyō Shibari" spells.
The latter was a simple binding spell, one that Kisuke performed and managed to technically defeat a semi-transformed Aizen with. While the latter, the one Silas was truly interested in, connects the space of one realm to another.
To perform it, one not only needed to know the incantation, but they also needed two large wooden posts to jut out from an open formation. Not only were the incantations not written on the scroll, but Silas also didn't have the two wooden posts.
But that hadn't mattered.
Kisuke had used this technique before, and Silas remembered most of the incantation vividly, as if he'd seen Kisuke perform it the day before. Silas didn't need wooden posts; his power amplified by the Hōgyoku would serve as the beacon!
If he could perfect this spell, he could open a portal to the Garganta, granting him access to Hueco Mundo!