It was precisely because of such achievements that Oetsu was invited to the Zero Division, ascending to the Soul King Palace. Meanwhile, the Bakkoto of the Kasumioji Clan was completely phased out.
Moreover, due to its instability, the Seireitei forbade the Kasumioji Clan from continuing their research.
In recent years, the casualties among the Gotei 13 Shinigami had been somewhat abnormal.
However, Yamamoto had not received any reports from the other divisions regarding this matter.
It seemed none of the divisions felt that the number of Shinigami deaths had increased by several dozen times compared to before.
Only the 1st Division, which possessed all the data on the Gotei 13's Shinigami, could detect the anomaly by analyzing the deaths across the squads.
Regarding this covert act of slaughtering Shinigami, Yamamoto believed that only the cruel nobles residing in the inner district would be capable of such deeds.
To this end, Yamamoto Genryūsai Shigekuni dispatched the 1st Division's third seat, Kisaragi Shin'etsu, to investigate the inner district and determine which family was responsible. But he never expected that, after some time, instead of receiving a report from Kisaragi, he would be reprimanded by the Central 46 today.
Although Yamamoto was the strongest Shinigami in a thousand years, and the Gotei 13 was the most powerful law enforcement force in the Seireitei, Yamamoto knew that he possessed the strength to 'protect' but not the ability to 'govern'.
Thus, after forcefully establishing the Gotei 13 in the Seireitei, Yamamoto did not rule as a tyrant. Instead, he only took charge of the Seireitei's defense, leaving its administration in the hands of the nobles.
Or rather, in the hands of the noble-led council known as the Central 46.
For some reason, Yamamoto felt that the so-called 'intruder' the Kasumioji Clan referred to might very well be his disciple, Kisaragi.
He did not know what Kisaragi had discovered that led him to infiltrate the Kasumioji Clan.
But now, Kisaragi had not returned, and the Central 46 had provided evidence of the intrusion. According to their agreement, the Gotei 13 had to apprehend the intruder and give the nobles an explanation.
Even if he wanted to exonerate Kisaragi, Yamamoto first needed to find him and learn what he had uncovered before he could hold the nobles accountable in turn.
"Captain Aikawa, for the time being, I ask that you increase patrol density in the inner district. Even if we cannot capture the intruder, we must prevent any further attacks on the nobles."
"Yes, Captain-Commander!"
"Then, I shall take my leave."
After bowing to Yamamoto, Aikawa turned and departed.
At a time like this, he needed to keep a constant watch over the inner district.
Otherwise, if another noble were attacked in his absence, it would be a true disgrace.
After Aikawa left, the Reiatsu emanating from Yamamoto suddenly eased, allowing everyone to relax. The earlier state of the Captain-Commander had been terrifying, as if he were a powder keg ready to explode at any moment.
"Everyone, recently, the mortality rate among Shinigami across the divisions has increased by several dozen times compared to the past."
Hearing this, many of the Captains were shocked, though none voiced their thoughts.
Kyoya was aware of the truth behind these Shinigami's deaths.
As for the other Captains, they paid little attention to the lower-ranked Shinigami.
As long as it wasn't their own friends or family who died, who had the time to mourn for others?
"Captain Yoruichi, Captain Kyoraku, Captain Shiba, your three divisions will immediately investigate this matter."
"Yes!"
Yoruichi, Kyoraku, and Shiba Isshin quickly acknowledged the order.
The 2nd Division, the Onmitsukido, specialized in reconnaissance, interrogation, intelligence, and assassination.
The 8th Division, the intelligence unit, handled external intelligence for the Seireitei.
The 10th Division, the patrol and security unit, was responsible for patrolling and guarding the outer district of the Seireitei.
"Captain Kyoya."
"Yes, Captain-Commander."
Hearing Yamamoto call his name, Kyoya stepped forward.
"The 11th Division is to enter a state of combat readiness. Once orders are given, be prepared to engage at any moment!"
"Yes, Captain-Commander."
After assigning the necessary tasks, Yamamoto addressed the remaining Captains: "The rest of you should also remain vigilant. If you encounter anything unusual, report it to me immediately to prevent further casualties among our Shinigami."
"Yes, Captain-Commander."
"Meeting adjourned!"
…
"So?"
"Last night, someone attacked the estate of a high-ranking noble family."
After leaving the 1st Division, Gin asked Kyoya about the main points discussed during the meeting.
"Then it has nothing to do with Aizen?"
"No, it's still connected."
Kyoya shook his head: "Based on the changes in the number of Shinigami deaths in each division, Captain-Commander deduced that there is a faction within the Seireitei secretly slaughtering Shinigami."
"Thus, he ordered the 2nd, 8th, and 10th Divisions to investigate jointly, while placing our 11th Division on standby for combat. Once orders are given, we move out immediately!"
"The faction responsible for slaughtering Shinigami undoubtedly has Aizen's hand in it."
"I suspect Aizen is fully aware of this faction, which is why he has increased his experiments during this time."
Kyoya said gravely, "Most likely, all the Shinigami who became Aizen's test subjects will be blamed on that faction, leaving Aizen completely untouchable."
Gin nodded.
'This was indeed Aizen's style.'
'No matter what he did, he always ensured there were no loose ends.'
"Don't worry."
Kyoya patted Gin Ichimaru's elbow, his brow twitching slightly.
'Damn this height difference!'
"As long as I'm here, Aizen won't be able to pose any threat to the members of the 11th Division."
"The moment my Observation Haki detects Aizen's presence near the 11th Division, I'll make sure to give him a big surprise!"
"Mmm."
Gin nodded.
The time Gin had spent by Kyoya's side was about the same as the time he had spent with Aizen.
Between Aizen and Kyoya, Gin had his own understanding.
Indeed, in Gin's eyes, Aizen was as deep and unfathomable as the ocean, giving off a suffocating sense of standing at the edge of an abyss just by being near him.
Kyoya, on the other hand, was like the sun in the sky… gentle and warm, yet blazing with intensity.
But the closer one got, the more terrifying Kyoya's presence became.
As for who was stronger between Kyoya and Aizen, Gin, with his current strength and insight, couldn't yet determine.
But Gin did know that Kyoya's Observation Haki could bypass the effects of Aizen's Zanpakuto, Kyoka Suigetsu, while Kyoya's own Zanpakuto was the strongest light-based Zanpakuto, capable of drastically enhancing his combat power.
In this regard, Kyoya held the advantage.
In Zanjutsu, Kyoya was undeniably the best.
Even Aizen cannot compare with him.
As for other aspects, Aizen, with his centuries of experience, surpassed Kyoya in Kido and combat experience.
In a fight between the two, Gin wouldn't be surprised by either outcome.
But he knew that if Aizen ever clashed with Kyoya, he would inevitably be exposed.
At that point, Aizen would no longer be able to stay in the Seireitei and would have to flee to the Living World or Hueco Mundo.
…
The Gotei 13's state of readiness made many Shinigami feel the weight of the tense atmosphere.
Especially after the Captains revealed the sharp increase in Shinigami's deaths recently, everyone suddenly realized that the comrades they hadn't seen in a while had actually been killed.
This crisis, where they didn't even know when their comrades had died, left the Gotei 13's Shinigami on edge.
Almost every day, they would take roll call to ensure no one had gone missing without anyone noticing.
Boom!
That night, Kyoya sat cross-legged on his bed, using Zanzen in place of sleep, when he suddenly sensed a clash of Reiatsu coming from the inner district.
Immediately, Kyoya stood up, grabbed his Captain's haori from the side, and threw it on. He then opened the window and leaped out.
"Captain!"
The moment Kyoya landed on the roof, he saw Gin rushing over with several seated officers.
"Captain, I just sensed Reiatsu Fluctuations in that direction..."
"Mmm."
Kyoya wasn't surprised that Gin had detected the Reiatsu Fluctuations.
After all, Gin was only a step away from 3rd-class Reiryoku and had trained in Observation Haki for five years.
Though he still hadn't learned it, his Reikaku had greatly improved.
Still, he could only vaguely sense the general direction… unless he moved closer or the Shinigami releasing the Reiatsu amplified it further.
"There's a Captain-level Reiatsu clash in that direction."
"One of them is Captain Aikawa of the 7th Division."
After explaining briefly to Gin, Kyoya added, "From the looks of it, Captain Aikawa seems to be at a disadvantage."
"I'll go back him up first. Gin, you take temporary command of the 11th Division. If orders for deployment come, immediately release your Reiatsu… I'll return as fast as I can."
"Got it."
Seeing Gin's acknowledgment, Kyoya didn't hesitate further. With a flash, he vanished from Gin and the others' sight.