Kizoku no Obocchan Dakedo, Sekai Heiwa no Tame ni Yuusha no Heroine wo Ubaimasu (Light Novel)

A man who while playing a game in Japan, died of cardiac arrest. In the brink of death, he was asked a favor by the Goddess of the eroge he was playing "After defeating The Great Demonic Lord, please save the world from the tyranny of the hero" to save the world. Using his knowledge of the current era, and his summoning arts, this is the story of a man who steals the heroines of the hero...