Demon Slayers vs Muzan Kibutsuji: Rematch is a battle between Demon Slayers Tanjiro Kamado, Zenitsu Agatsuma, Inosuke Hashibira, Kanao Tsuyuri, and Hashira Giyu Tomioka, Mitsuri Kanroji, Obanai Iguro, Gyomei Himejima, Sanemi Shinazugawa, and Demon Yushiro against Demon Lord Muzan Kibutsuji. It occurs immediately after the Infinity Castle is destroyed.
After all the Hashira present in the fight were knocked down by Muzan Kibutsuji, Tanjiro Kamado regains his consciousness with the help of Yushiro's medicine, and uses Hinokami Kagura: Beneficent Radiance to cut off Muzan's arms. Tanjiro later on challenges him to end the battle.
Muzan's defeat while significant, would prove to be a costly victory for the Demon Slayers, leaving scores of members deceased, dozens mauled and heavily injured and many on the verge of death.
Tanjiro turns into a Demon, starting a new battle.