Royal Guard

The Royal Guard, known in Soul Society as the Zero Division, is the Shinigami force devoted solely to shielding the Soul King and the Soul King Palace. It commands extraordinary combat and executive power, standing above every other body in the realm, yet its very existence is kept from common knowledge. Because the Soul King anchors the balance of the Three Worlds, the Guard holds to that single charge and refuses to enter the Gotei 13's wars, even against threats as grave as Sōsuke Aizen. Each of its members carries the Ōken sealed into their very bones and is granted a personal city inside the palace.

Membership is reserved for Shinigami whom the Soul King himself acknowledges for leaving a profound mark on the realm's history, and the Guard often elevates sitting Gotei 13 captains into its ranks. It fields no rank-and-file soldiers whatsoever, only five members, every one a captain, whose united strength dwarfs the whole of the Gotei 13; Ichibe'e Hyōsube leads them. So immense is each member's spiritual power that unleashing it unchecked could unravel the Three Worlds, so four of them bind their true strength by using one another's lives as living seals, an arrangement that also locks away their Bankai. When they leave the palace they descend aboard a colossal pillar, the Tenchūren, which slams down on arrival and must be fired back home by Kūkaku Shiba's cannon.

The five bear grand titles tied to the compass and to the crafts they perfected. Ichibe'e Hyōsube, the high priest who names all things, serves as their commanding officer. Tenjirō Kirinji, the Divine General of the East, is a master of healing arts; Kirio Hikifune, General of the South, shapes spiritual nourishment; Ōetsu Nimaiya, General of the West, is the smith who created the Asauchi from which every Zanpakutō is born; and Senjumaru Shutara, General of the North, is credited in supplementary works with inventing the Shinigami uniform itself, the very feat that won her promotion. Their emblem draws on the winter daphne flower set within the Gotei 13's rhombus.