Rule, King of the Three Realms

"Toshiro, once one's strength reached the level of the Soul King, individual power was still important, but the ability to strengthen one's subordinates became even more important!"

"Take Hueco Mundo as an example. If the King of Hueco Mundo had to kill every opponent himself, he might get so bored he'd commit suicide."

Only with enough subordinates could the strength of a ruler of one realm—or even the ruler of the Three Realms—truly be displayed.

"In this respect, the King of Hueco Mundo clearly understood it very well. Generation after generation of his subordinates had grown stronger, each era surpassing the last. If Soul Society and Hueco Mundo were to wage a large-scale war, then even if the King of Hueco Mundo did not take action..."