The Reformation of the World as Overseen by a Realist Demon King, Vol. 1 (manga)

HOW DO YOU STOP A HERO? Van must be convinced to leave Zoltan before he brings greater harm to this peaceful corner of the world. Changing the mind of one so zealously devoted to twisted beliefs won’t be easy, though. Red and the others decide to start by swaying Van’s companions, Lavender and Ljubo, hoping the Hero will listen to his allies. But will that be enough? Van needs someone who will get him to question his decisions and guide him to a better path…