"I've seen the Twelfth Division's experiment records."
"At the time, a researcher in the Twelfth Division named Yushima Oshu developed an artificial soul called a 'Modified Soul' based on 'Temporary Souls.'"
Even Urahara Kisuke could not help but admire the researcher named Yushima Oshu when he spoke of this.
What Temporary Souls created were merely artificial souls with extremely short lifespans. If they were not put to use during that brief period, Temporary Souls would dissipate and return to a reishi state.
Modified Souls, however, were different. They were artificial souls that could exist for a long time, virtually no different from real souls.
As long as a Modified Soul was made into a Gigai, it could be preserved permanently.
After creating the Modified Soul, Yushima Oshu submitted a research proposal to the Seireitei—the Soul Soldier Project!
The so-called Soul Soldier Project involved using the spiritual pressure of the Seireitei's powerful Captains as material for Modified Souls, creating Modified Souls that possessed the Captains' memories.
Then, the Captains' spiritual pressure would be used to create corresponding Reikaku.
Once the corresponding Modified Soul was placed into its matching Reikaku, those Reikaku would become superweapons possessing the Captains' memories and strength.
It had to be said that if this research had been approved, the Seireitei's strength could practically have doubled.
However, the research was ultimately rejected by Central 46.
Indeed, the Soul Soldier Project could have caused the Gotei 13's strength to soar.
But at the same time, the project carried a hidden danger.
That was, if these Soul Soldiers, who possessed the Captains' memories and strength, ever launched a rebellion against the Seireitei or secretly replaced certain Captains, how would anyone tell the difference?
Thus, Central 46 rejected Yushima Oshu's proposal, classified Modified Souls as prohibited research, and even issued an