Yoruichi didn't quite believe Yinsen. What did he mean, defeating him was harder than replacing the Soul King? How could that be possible? Yet faintly, she had the feeling that Yinsen was telling the truth!
"I must be crazy!"
As the Family Head of the Shihōin Family, one of the greatest noble houses in Soul Society, Yoruichi Shihoin understood the significance of the Soul King to this world better than most beings in Soul Society—or rather, better than most beings in this world.
The more she understood, the harder it was to believe Yinsen's joking-sounding words. Yet despite how unbelievable they were, part of her felt they were true. If she hadn't been certain that Yinsen would never use Kyoka Suigetsu on her, she would have thought she had already been hypnotized, which was why her mind was so muddled.
Muddled or not, Yoruichi began training hard again. Even though her rate of progress was slowing further and further, and she was gradually beginning to touch upon a bottleneck, she did not give up.
Yinsen had his own views on the so-called bottlenecks of this world.
If the spiritual particles possessed by Shinigami were compared to positively aligned spiritual particles, then those used by Hollows could be considered negatively aligned spiritual particles.
The bodies of Shinigami, composed of positively aligned spiritual particles, had a certain capacity limit. That limit varied according to individual talent, but there was ultimately a ceiling. Once it was reached, they could no longer increase their own spiritual power.
The solution proposed by people like Kisuke Urahara and Aizen was to break the barrier between Shinigami and Hollows. In other words, they wanted to alter the nature of a Shinigami's body so that this "container" could hold not only positively aligned spiritual particles, but negatively aligned