The Executioner and Her Way of Life, Vol. 5 (manga) — Mato Sato

Menou and her allies succeed in executing Manon Libelle, the mastermind behind the drug monstrine—but they are immediately attacked by one of the Four Major Human Errors who once destroyed the world, Pandæmonium. Up against an enemy who creates infinitely many monsters from her flesh, revives herself at will, and treats life and death as mere entertainment, Menou is driven into a corner. But just as she prepares herself for the end, the princess knight appears…