The Demon Slayer Corps stands as humanity's only defense against Demons. But what would have happened if it never existed?

Yoriichi himself has shown that he can single-handedly kill Muzan in an encounter between the two. The only reason the latter survived is that he split himself into thousands of tiny pieces to escape.

the Demon King Muzan is defeated, and Nezuko’s humanity is restored. Demons are purged from the world, the Tanjiro and the rest of the Demon Slayer Corps are free to hang up their swords and ...