Demon Slayer creator, Koyoharu Gotouge has some interesting and creative processes they use when formulating their characters. The critically acclaimed anime series has garnered massive popularity and an avid fanbase since its release, as well as theatrical movies, a video game, and three seasons of the anime, with a fourth on the way. One of the series' coolest characters, Sakonji Urokodaki, was going to look very different initially.
https://screenrant.com/demon-slayer-urokodaki-mask-meaning-changed-fix/