Kanzen Saimin

Kanzen Saimin, rendered as Complete Hypnosis, is the chief ability of Kyōka Suigetsu, the Shikai belonging to Sōsuke Aizen. Aizen himself describes it as a power that so thoroughly scrambles the senses that a fly can seem a dragon and a swamp a flower garden.

The single requirement is a hypnotic ritual: anyone who witnesses Kyōka Suigetsu's release even once falls under its sway forever, yielding to every later release no matter how much time has passed, as the Visored proved by staying affected a hundred and ten years on. Once caught, a target can be made to misjudge appearance, shape, mass, texture, and scent alike, and awareness of the ruse offers no defense. Aizen can release in silence to hide the ritual, conjure decoy copies of himself, and craft illusions detailed enough to fake his own corpse or make a hall of dead councilors look alive and in session. The hypnosis does have limits: it cannot reach the blind, such as Kaname Tōsen, nor anyone who has never seen the release, which is why Ichigo Kurosaki stood the best chance against him. The one certain escape, a secret only Gin Ichimaru ever pried loose, is to touch Kyōka Suigetsu's blade before the spell takes hold.

Kanzen Saimin belongs to Sōsuke Aizen through Kyōka Suigetsu. In Ryōgo Narita's novels, Tokinada Tsunayashiro reproduces it using his clan's ancestral Zanpakutō, Enrakyōten, though his weaker Reiatsu makes the effect less potent and forces him to renew it constantly.