Zero has confirmed that only he can hear that voice; even Starrk, currently the Espada with the strongest Reiatsu, cannot hear it.
After sending several Espada out in rotation to search for Vasto Lorde, Zero returned to his office to look at the documents, all of which were taken from a black box. These documents contained Aizen's early information about the creation, usage, and effects of the Hōgyoku.
The material used to create the Hōgyoku is refined from a large number of Soul Reaper soul fragments, specifically the soul fragments Aizen collected during the Seireitei explosion.
Ultimately, the Hōgyoku was formed by a certain Reishi Arts, Aizen didn't record in any documents, but presumably he remembered it.
According to Aizen's speculation recorded in the documents: even an unfinished Hōgyoku can make what a person desires happen according to their own wishes, and thus ultimately materialize it, the only condition being that the dreamer himself must have the power to realize that wish.
However, since the Hōgyoku is not fully satisfied, or rather, not completely completed, the fulfillment of this wish sometimes fails. In the best-case scenario, after achieving a certain degree of completion, the Hōgyoku falls back into slumber, and one can only wait for the next opportunity...
"What I'm saying is, I want to defeat Yama-jii, but I'm currently limited by my own strength. After the Hōgyoku senses my intentions, it will arrange several opportunities for me to accomplish this... That's really awesome."
After reading the information, Zero immediately understood and was filled with disbelief. It was just like Dragon Ball! It was like having a cheat code.
However, the Hōgyoku needs to be handled more subtly, and it will take some time to fulfill your wish.
"The only downside is that this Hōgyoku isn't in its complete form yet. Each use will plunge you into a dormant state lasting several months or even years, which might cause unexpected problems with your wishes along the way..."
After studying it in his office and realizing its importance, Zero no longer did anything foolish like letting all the Espada take it.
According to Aizen's latest information, he used the Hōgyoku to forcibly evolve twenty Giant Hollows into Adjuchas, of which only ten succeeded.
The Hollows that invaded Hirako and the others' bodies originated from here.
Because of Aizen's use of it, the Hōgyoku is currently in a dormant state and has not yet awakened; this situation cannot be eradicated until it fully becomes its complete form.
As Zero continued reviewing the documents, he came across the term 'Soul King Fragment' again... which was indeed a fragment of Reiryoku scattered by the Soul King throughout the world.
Only exceptionally gifted Soul Reaper or mediums in the World of the Living who are born with powerful Reiryoku could possibly possess Soul King Fragment... Note that it is 'possibly' rather than 'certainly'.
Therefore, according to Aizen's estimates, even with incredible luck and collecting one fragment every year, fifty fragments would still be needed to complete the Hōgyoku, meaning it would take fifty years...
"Is the Soul King really that powerful? I thought he was just some guy with a little Reiryoku, at most a symbol of power to keep the Three Worlds at peace..."
Zero raised an eyebrow, a bold idea popping into her head. "Wait, fifty fragments smaller than a fingernail are enough for the Hōgyoku to evolve into its perfect form, so if I go to the Soul King Palace and chop down the Soul King, wouldn't I have everything?"
Overthrowing the old system of Soul Society is equivalent to challenging the Soul King. Zero once witnessed the Zero Division descending from the sky, indicating that the Soul King Palace is above the Seireitei.
The Gotei 13 only protects the Seireitei, while the Zero Division protects the Soul King Palace. If I were to go and fight the Soul King, I would only need to face the small Zero Division.
According to the information sent back by 007, the Zero Division has added Kirio Hikifune, the Captain of the Twelfth Division, and Senjumaru Shutara, the former Vice-Captain of the Second Division, making it only five people.
Zero was tempted to make the Hōgyoku fully complete, but he also remembered what Hana-nee had said, "The combined fighting power of the three of them is comparable to that of the entire Gotei 13."
Therefore, even if we want to attack the Soul King Palace, we need to plan carefully and at least calculate our combat strength so that we don't get wiped out as soon as we arrive.
While Zero was researching how to use the Hōgyoku, Urahara had already escaped to the World of the Living.
After Urahara created special Gigai) that could isolate Reiatsu for the Captain-level, he hid them in the World of the Living, where Tessai Tsukabishi used Kidō) to suppress them and prevent them from going berserk.
He conducted experiments every day, trying to find a way to break free from Hollowfication, but progress was stalled until he discovered the existence of the Quincy...
Kisuke Urahara, Yoruichi Shihōin Shihouin, Tessai Tsukabishi, and eight Captain-level who are not yet able to control their Hollowfication have become a powerful force roaming the World of the Living.
Given the current weakness of the Seireitei's defenses, the Central 46 have neither issued nor been able to issue orders to pursue them, as they are unable to detect Urahara and his group's Reiatsu reactions.
Moreover, replenishing the missing combat power of the Gotei 13 has become their top priority. More than half of the Captain-level are missing, which is the most serious loss of Captain-level in the Gotei 13 since the Quincy nine hundred years ago.
Furthermore, due to the lack of Captain-level, some external forces within Soul Society are becoming increasingly restless...
101 years ago, due to the Hollowfication Incident Captains, there was a severe shortage of Captain-level combatants. Kaien Shiba accepted Ukitake's invitation and became the Vice-Captain of the Gotei 13.
100 years ago, Mayuri Kurotsuchi demonstrated his Bankai and took over the Twelfth Division completely.
In the same year, Aizen and Tōsen temporarily became Captains, their actual positions being Vice-Captains, and they were enduring this situation for the time being.
Subsequently, in order to restore the fighting strength of the Gotei 13, Yama-jii and Hana-nee devised a plan to lure the directionally Kenpachi Zaraki to the Gotei 13.
The name 'Kenpachi' can only be used by one person, and unsurprisingly, Kiganjō was killed on the spot, without even being able to use his Bankai...
Because Kenpachi Zaraki's power was too strong, and he was still not fully in Shikai and Bankai, Yama-jii came to teach him swordsmanship... but gave up after only one day, Kenpachi Zaraki was too strong when he used swordsmanship.
Yama-jii also told Kenpachi Zaraki that if he used swordsmanship to fight, he would not be able to enjoy the battle. Therefore, Zaraki temporarily gave up using swordsmanship.
Kenpachi began his life of conquest, leaving no rebel unpunished and slaying them all.
The Expeditionary Force's camp in the District 80 West Rukongai.
"Captain Amagai, the Seireitei is short so many Captains, aren't you going to compete for one? Even Kenpachi from the Zaraki District has been drawn to him!"
"Competing now is pointless; it will only hinder our progress. Our skills aren't up to par yet..."
Amagai Shūsuke responded to his adjutant Kifune Ri, saying that the two of them were the Vice-Captain of the Expeditionary Force, although they only controlled a few dozen people.
Upon hearing this, Kibune clenched his fist. His life motto was "to lack power is a sin." Kibune, who believed he had gained some strength, wanted to become the Vice-Captain to prove himself.
Amagai saw through his thoughts and secretly scoffed. The young man was too impatient and lacked patience; he would fail sooner or later...
If Amagai doesn't become the Captain, others generally won't appoint Kibune, who is somewhat extreme, as the Vice-Captain. Moreover, Kibune has a history of using teammates as Bait... Therefore, Kifune Ri can only rely on Amagai.
By this Amagai had already found out who killed his father. It was Nangong Ling, who had brought his father's body back that day. Unfortunately, by the time he learned Bankai, Nangong Ling had already defected.
In fact, even if Nangong Ling hadn't run away, Amagai knew that his strength was insignificant compared to Nangong Ling's.
As the Seireitei continued to develop, Aizen once again consulted some information through the Great Spirit Book Gallery, and he was pleasantly surprised to discover that Kisuke Urahara already possessed the Hōgyoku.
Aizen realized he had miscalculated. If he had known earlier that Urahara possessed the Hōgyoku, he would never have let him defect so easily.
At the very least, we must seize his Hōgyoku and then use the Central 46 to force him to escape.
Now, his Hōgyoku has been stolen by Nangong Ling, and he's trying to recreate it, but unfortunately, the material problem is proving difficult to solve...
95 years ago, Aizen became the Fifth Division Captain, and Gin Ichimaru, who had been used as cannon fodder but shamelessly followed Aizen, became the Vice-Captain... By this time, Aizen already suspected Gin. He didn't even complain about being used as cannon fodder? What a load of rubbish!
Ninety-three years ago, Kaname Tōsen became the Captain of the Ninth Division.
In the same year, Sajin Komamura, who had been kept under wraps and secretly trained by Yama-jii -Ya, suddenly became the Captain of the Seventh Division.
Even more suddenly, the head of the Shiba branch family joined the Gotei 13 at the invitation of Kaien Shiba and was appointed as the Captain of the Tenth Division.
Another year passed, and a genius girl emerged from the Fon Clan, a minor noble Shihoin Family. She mastered Bankai and inherited the position of Second Division Captain. This girl was Soi Fon.
Currently, the Seireitei has not yet fully filled its Captain-level, but it is only missing the position of Third Division Captain.
Having realized that controlling Hueco Mundo was hopeless, Aizen began to secretly develop his power in Soul Society... At this time, he noticed the Expeditionary Force in the borderlands.
The Wandenreich has detected the changes in Soul Society, and if possible, this is undoubtedly the best time to attack the Seireitei.
However, following Yhwach's instructions before falling into slumber, everything had to wait until Emperor Yhwach awoke. Therefore, Jugram Haschwalth held back and continued to have the Quincy secretly hunt Hollows on the edge of Hueco Mundo.
At this time, the Hueco Mundo was conducting a groundbreaking experiment.
In a secret chamber shrouded by Barrier, Grimmjow, his entire body wrapped in white bandages, even his nostrils were covered, had been kneeling quietly before the Hōgyoku for five months.
Those bandages not only concealed Grimmjow's appearance, but also hid and suppressed all his Reiatsu within his body. At this moment, Grimmjow was like a lifeless statue.
Finally, as if emerging from a cocoon, a small crack appeared on his back, and a powerful Reiatsu burst forth from within... Upon seeing this, the people in the Control Room immediately ran to report it.
"Report: The first Vasto Lorde Experimental Subject is about to complete its evolution; the Reiatsu is fluctuating violently."
"Okay, go down!"
Upon receiving the report, Zero immediately used Shunpo to reach the entrance of the secret chamber where Grimmjow was, dispelling the Barrier and opening the door before entering.
Just then, with a snap, the pure Reiatsu tore through the white bandages, Grimmjow emerged naked from his cocoon, his appearance drastically changed.
Only the Hollow Hole in his abdomen and the remnants of a bone mask on his cheeks prove that he was once a ghost...
Grimmjow glanced at his hands, then looked up and chuckled softly, "Heh heh..."
"Ha ha, power, power, unprecedented power!" Grimmjow's laughter grew increasingly unrestrained, accompanied by crazed exclamations.
He was bound in bandages for months, following Zero's instructions, and his only thought each day was to become stronger.
"Excellent, a complete success, and the improvement is significant!"
As Zero spoke, Grimmjow's transformation continued. The bandages scattered on the ground suddenly turned into Reishi Condensation and coalesced into a Zanpakuto belonging to Grimmjow.
This sword contains Grimmjow's original form and power.