Bright Red Blade

The 49th anime episode and fifth of the third season adapts portions of chapters 110 through 113, taking its title from chapter 113. Muichiro reaches Kanamori and clears the path to the work shed, only to be intercepted by Upper Rank Five, Gyokko. In the settlement, the Love Hashira Mitsuri Kanroji cuts down swarms of fish demons and saves the chief, Tecchin, from being crushed. Cornered alongside Genya, Tanjiro witnesses an inherited memory and watches his blade ignite into a brilliant red, a transformation that finally lets him overcome Hantengu's manifestations.

Mitsuri and Gyokko

Mitsuri arrives just in time, using her whip-like Nichirin sword to eviscerate the giant fish demon holding Tecchin. Meanwhile Gyokko unveils a grotesque sculpture made from mutilated swordsmiths, enraging Muichiro, who learns the demon can be killed by decapitation since he dodges every neck strike.

The crimson sword

Trapped under debris, Nezuko grips Tanjiro's blade and coats it in her blood before using Exploding Blood, turning the steel bright red. Tanjiro experiences a vision of his ancestor Sumiyoshi watching a black-bladed swordsman whose sword likewise reddened in battle.

Three felled at once

Empowered, Tanjiro performs Sun Halo Dragon Head Dance and slices through Urogi, Karaku, and Sekido in one fluid motion. Sekido recognizes the red blade from Muzan's memories as belonging to the swordsman who once nearly destroyed the demon progenitor. Searching for the final demon, Tanjiro finds Genya transformed, sporting fangs and altered eyes.

The second eyecatcher loosely recreates chapter 111's cover. The anime adjusts Karaku's destruction of the building, showing him chase the siblings inside and attack twice rather than leveling it in a single motion. Gyokko's goldfish fire their needles upward at a rooftop Muichiro in the adaptation, reversing the manga's overhead angle. The English dub also contains a noted blooper where Muichiro's actor says "feeling" instead of "fleeing" while comparing the demons' instincts.