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.
Webfurthermore, the analysis of tanjirou’s journey leads to a revelation of the inner transformation that he experiences, which is the positive change arc, and thus, making.
Webtanjiro certainly did a lot of good with his water breathing techniques, but his ability to use sun breathing both gives him an edge in battle and allows him to stand.