Chapter 222: Ashido and Muramasa
Shinigami needed permission to use the "Senkaimon," which at least officially allowed for the control of most Shinigami movements. However, controlling the movements of Hollows in Hueco Mundo was impossible.
Hollows were once human souls, born when the "Chain of Fate" consumed their souls. They were born into the World of the Living, and only by devouring enough souls did they become powerful enough to open a Garganta to Hueco Mundo.
Even if all the available forces of the Soul Society and Hueco Mundo were mobilized, it wouldn't be enough to monitor these Hollows, which could be born and leave at any moment.
Harribel remained silent, cautiously observing the young Shinigami who had already defeated Aizen.
"Two things." Naruto raised two fingers. "First, the Seireitei will register all Arrancar with captain-level power and above."
"Spiritual pressure, abilities, age..."
He put down one finger and continued, "Without the Seireitei's permission, no captain-level Arrancar or higher is allowed to engage in conflict."
Grimmjow sneered and scoffed, "So you're going to cage us?"
"Other than that, the Soul Society won't interfere with Hueco Mundo's affairs."