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

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, Pand-nium. 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-