Bright Red Blade

Through an inherited memory, Tanjiro Kamado glimpses two ancestors discussing a swordsman with earrings whose normally black blade would turn red in battle. Tanjiro connects that figure's sword to his own, noting how both change color and how his shift came from Nezuko's Blood Demon Art. Despite his exhaustion and wounds, he resolves to live up to everyone who has supported him.

Sekido, Karaku, and Urogi sneer and charge, but the red blade triggers Muzan Kibutsuji's memories within them. The forms recognize it as the weapon of the slayer who nearly destroyed their master, and Tanjiro's stance eerily mirrors that swordsman's as he readies his swing. He cuts all three down with Hinokami Kagura: Sun Halo Dragon Head Dance.

After decapitating the trio, Tanjiro recognizes the burning sensation as the same one he felt landing the killing blow on Gyutaro in the Entertainment District. He searches for Aizetsu and finds him pinned to a tree by his own spear, with Genya Shinazugawa standing before him holding the severed head. Relief gives way to horror as Genya turns to show a partly demonic face. A frustrated Karaku interrupts, complaining that he cannot regenerate and that his wounds keep burning.

Unsure whether killing the four emotion demons truly defeats the Upper Rank, Tanjiro catches the scent of a fifth body. Genya seizes him, vowing that he will slay the Upper Rank and become a Hashira instead. Realizing Genya has not lost himself to demon instinct, Tanjiro and Nezuko back his goal, surprising him. When Sekido fires lightning, the group splits so Genya can hunt the fifth form, and Tanjiro spots it cowering in the bushes, whispering encouragement to itself.

This Swordsmith Village Arc chapter appeared in Weekly Shonen Jump issue 28 of 2018, dated June 11th, and is collected in Volume 13. It was adapted across Episodes 49 and 50 of the anime. The installment formally links Tanjiro to Yoriichi Tsugikuni through inherited memory, showcases the power of the red blade against Hantengu's forms, and reveals Genya's demonic features for the first time.