Demon Slayer Manga Chapter 172

Steel begins to glow. Under the strain of the mark and burning will, the blades of the slayers turn bright red, a color that burns demon flesh and slows their healing. Gyomei’s flail, Sanemi’s sword, and Muichiro’s stabbing blade all press into Kokushibo at once.

For the first time in three hundred years, the Upper Rank One feels the fight slipping away from him. Pinned by roots, stabbed through the body, and battered from every side, he faces a choice no demon enjoys: change, or die in this hall like a cornered animal.