Back then, because of Retsu Unohana, Zaraki had been reduced to a "weakling" with only Seat Officer-level reiatsu.
Although his reiatsu had risen to Captain-level during his battle with Ailin Kenpachi, in Unohana Yachiru's eyes, even Captain-level Zaraki was still "weak."
To strengthen Zaraki, Retsu Unohana had even asked Captain-Commander Yamamoto to teach Zaraki "swordsmanship."
However, after foreseeing Zaraki's potential, Captain-Commander Yamamoto had still resorted to tricks, making Zaraki give up on learning so-called "swordsmanship" himself.
In Captain-Commander Yamamoto's view, Yhwach had already been killed by him, so the only ones who could cause problems in the Seireitei were the Shinigami.
To keep the damage inflicted upon the Seireitei within acceptable limits, "weakening" the Shinigami was an extremely viable measure.
The Hibiki Hoshino incident had further convinced Captain-Commander Yamamoto that his decision was correct.
Thinking about it carefully, if the Shinigami had not been "weakened," then with the terrifying ability of Hibiki Hoshino's Zanpakuto, overturning the entire Seireitei would not have been difficult at all.
By then, even if he had killed Hibiki Hoshino, the damage to the Seireitei would not have been any less than the explosion at the Modified Soul research facility.
One had to know that the Modified Soul project had nearly destroyed one-tenth of the Seireitei.
Ever since witnessing the destruction that "scientific research" could bring to the Seireitei, Captain-Commander Yamamoto had forbidden all research related to souls.
Not only that, even Kido involving time and space had become "Forbidden Jutsu." Once used, one would become a "criminal" of the Seireitei.
However, even though they had implemented a series of measures, people's pursuit of "strength," hidden deep within their souls, was not so easily erased.
Aizen had "selflessly" passed down his cultivation experience, greatly increasing the potential of later generations of Shinigami.
Perhaps that was why