Kaikyō Kotei

The Dangai, or Precipice World, is a narrow passage joining the Human World to Soul Society, sealed off from ordinary space and time and adrift within the void of Garganta. Threading through it is the Kōryū, a relentless current that seizes any soul it touches and pins them against the walls. Kaikyō Kotei is the countermeasure that brings this current to a halt so that people may pass without being caught.

Two approaches exist. In the standard version, a large contingent of low-ranking Shinigami enters the corridor together and channels their combined Reiatsu into the walls to hold the current down. A single individual with enormous spiritual reserves can achieve the same effect alone, but only after embedding four small forked blades at points along the passage and keeping himself linked to them the entire time. Even then the hold is temporary; by Isshin Kurosaki's reckoning, a caster of his caliber can sustain it for no more than two thousand hours as measured inside the Dangai, where time is compressed roughly two thousand fold.

Ordinary Shinigami perform the fixation in numbers whenever the corridor must be secured. Isshin Kurosaki carries it out single-handedly during the war against Sousuke Aizen, freezing the current long enough to drill Ichigo Kurosaki in the final technique Saigo no Getsuga Tenshō deep within the Precipice World.