A Sword from Over 300 Years Ago

Tanjiro becomes disappointed after he discovers the sword rusted. However, a swole Hagenazuka appears, revealing he trained in solitude to be able to forge a better sword for Tanjiro. As such, he offers to restore the rusty sword, giving Tanjiro another one in the meantime. That night, while trying to befriend Genya, swordsmith Kanamori is brutally devoured by Gyokko who, alongside Hantengu, has found the village. After Muichiro is moved by Tanjiro's sense of kindness towards others, Hantengu enters their room, only to be quickly beheaded. However, two individual demons regenerate from the severed body parts, each with different, powerful abilities. After one of them blasts Muichiro far away, the other nearly electrocutes Tanjiro with a staff, before Genya appears and beheads them both with a sawed-off shotgun and a Nichirin knife. However, Hantengu again duplicates, and one of the demons deafens Tanjiro with a sonic attack while Nezuko tries to defend Genya. Meanwhile, Muichiro runs back to assist, but finds Kotetsu in peril from one of Gyokko's spawn. Initially electing not to help him, he saves him just before being eaten after remembering about the importance of kindness with others.