Retsu Unohana did not distrust Yuko. In fact, Yuko suited her quite well; otherwise, she would not be sitting here calmly listening to her explanation.
Because no matter how one looked at it, the evidence from back then had all pointed to Kisuke Urahara, and it was also a fact that items related to Hollowfication experiments had been found in the 12th Division.
Even if it had been a frame-up, they still needed to produce evidence, right?
" The Hogyoku wasn't an ordinary experimental tool." Yoruichi took over, her golden eyes fixed on Retsu Unohana. "With the Hogyoku already completely fused into Kuchiki Rukia's body, there's only one way to remove it without damaging it."
Retsu Unohana lifted her teacup and blew on the floating leaves without offering an opinion.
"Soukyoku."
Retsu Unohana's expression shifted slightly.
Yuko said calmly, "Removing the Hogyoku requires the ability to instantly vaporize a soul. Looking at the entire Soul Society, the only thing most likely capable of doing that is the Soukyoku."
The Soukyoku was not the only solution. Captain-General Yamamoto's abilities could achieve it as well. But obviously, Aizen had no way to control the old man and make him work for him.
And the Soukyoku...
It was an execution tool used to execute criminals, and the ones who judged criminals were that group of useless men with empty titles. Controlling them was obviously easier than using any other method.
Retsu Unohana pondered for a moment before shaking her head. "It's very reasonable. But how did Captain Aizen determine that Kuchiki Rukia would receive a severe sentence from Central 46?"
One had to understand that before the verdict was issued, almost no one would have thought Kuchiki Rukia would be sentenced to death.
For no other reason than the Kuchiki Family's prestige alone.