Throughout the final hours of combat, Muzan believes he is simply suffering fatigue from battling multiple marked Hashira simultaneously. The terrifying reality dawns on him far too late: his body is waging a losing war against Tamayo's synthetic concoction. The compound contains four distinct, sequential stages designed to dismantle demon physiology from the inside out.
The first component was an attempted human conversion agent. While Muzan successfully neutralized that initial phase, his biology was forced to expend enormous energy decomposing it. The second stage was an aggressive aging poison. By the time Muzan realizes why his movements feel sluggish, the poison has aged his internal organs by fifty years per minute, adding roughly 9,000 years of cellular damage to his physical body over a three-hour span.
The third phase systematically blocked his primary escape mechanism: cellular division. Centuries earlier, Muzan survived an encounter with the legendary swordsman Yoriichi Tsugikuni by detonating his body into 1,800 separate flesh fragments. Tamayo's compound locked his cellular membranes, making division impossible. The fourth and final stage triggered rapid cellular destruction, causing his internal tissue to rot while he desperately tried to defend against the blades of the Corps.
