Muzan spent his immortal life trying to find the blue spider lily used for the medicine that turned him into a demon with no luck.
Webthe secret ingredient in muzan’s treatment was none other than the rare blue spider lily, a flower steeped in legend and mystery.
Webmichikatsu agreed and muzan gave him an extremely high concentration of his blood, emerging three days later transformed and taking the name kokushibo.
Webdespite his fearsome reputation among slayers and demons alike, muzan had an illness that almost took his life in demon slayer, resulting in his intense fear of.