Sosuke Aizen of Bleach, who claimed that his Zanpakuto's ability was a perfect power, dominated the heroes of the Soul Society with it. With the help of Kyoka Suigestu's Full Hypnosis, his enemies can be duped in a nearly perfect illusion by entirely warping and manipulating their five senses. Aizen is virtually impenetrable by people under the power of Kyoka Suigetsu, whether he is using his own body as a decoy in battle, concealing his presence, or building a landscape of his choice. That is not fully accurate, though, as the show did mention several flaws.
The most closely guarded secret, learned only by Gin Ichimaru, is that if the blade was touched before the illusion began, it could be avoided – which almost resulted in Aizen's death. Because seeing Kyoka Suigetsu's release was a requirement for being eternally captured by the illusionary power, Kaname Tsen was unaffected by the illusions due to his blindness. Those with high levels of spirit power perception could also detect anomalies, even if they didn't fully understand why. However, there were other flaws in the Zanpakuto that were not explicitly mentioned during Bleach.
Aizen's Kyoka Suigetsu necessitates limitless imagination and knowledge
There was also the feeling of abnormalities inside the illusion itself. In Bleach's "Soul Society" arc, Aizen pretended to be dead and made a fake corpse to serve as his stand-in so that he could wander freely throughout the Soul Society. Retsu Unohana examined the phony corpse and discovered a problem with its makeup, even though she wasn't exactly sure why. Though he was ultimately unable to duplicate it completely, this meant that Aizen needed to have a perfect understanding of the specifics of a Soul Reaper's body in order to deceive the Captain of the 4th Division.
This is a key component of the illusionary method. Aizen is frequently depicted constructing simple illusions during actual combat, making it harder for his opponents to investigate what they are seeing and maximizing the effectiveness of the illusion. Aizen spent hundreds of years studying, passing on knowledge, and perhaps expanding his knowledge such that he could create illusions that would deceive specialists in a variety of professions, including surgery. Aizen must understand and visualize the illusion in order to fool his opponents, much like Gremmy did in the second half of the Thousand-Year Blood War. Unohana was able to see through it, demonstrating that she was more skilled than Aizen in creating a convincing physique.
Arrancar from Bleach has the power to avoid Aizen's total hypnosis
Arrancar can trace reiatsu through the air or on the ground using their pesquisa talent, which enables them to mentally identify the position of spirit energy. The ability to exactly locate someone was only briefly demonstrated in Bleach by Nnoitra Gilga in Los Nochas and Grimmjow Jaegerjaquez and his Fracción in Karakura Town. This is one of Aizen's Zanpakuto's toughest counters, if not the only one. While Aizen can conceal his reiatsu, the power disregards this and locates a target over a wide area. Kyoka Suigetsu was never able to defeat the Arrancar.
Aizen used Kyoka Suigetsu, an absurdly potent power, for unnatural purposes, but its potency was primarily intellectual rather than physical. Aizen usually used simple illusions to trick his adversaries. Even though it was already too late, he was exposed when he utilized it as part of a lengthier trick. In reality, The Complete Hypnosis and its faultless illusions had several issues.