The self-proclaimed "Son of the Soul King", his entire mission was to rid the world of its impurities. Those impurities being the other spiritually enhanced beings, to include Hollows, Shinigami, Bounts, Witches and Fullbringers. No one was safe from his wrath if they stepped out of line. His meticulous culmination of the Quincy was seen as a force to be reckoned with, and with their ability to destroy souls the Shinigami had to do something in order to keep the balance.

As such, a war ensues, leaving the man a husk of his former self as he sits upon his throne, his loyal subjects awaiting the day he awakens.