but that wasn't the case with Tanjiro. His family was killed by Muzan but if the Demon King had stayed in that house to take the protagonist's life or Giyuu Tomioka had shown up later, the truth ...

Demon Slayer: Infinity Castle will split its gigantic arc over three separate feature-length films, placing Tanjiro and the Demon Slayer Corps against Muzan and his strongest, demonic lieutenants.