u/U_Ok7

It starts where the hero party is going to fight the demon king, demon king tempts the party to join his cause and rule the world, MC of the story agrees and betrays the hero party and joins the demon king's side. The characters if I remember correctly are a half succubus maid, a hot fox eared milf, a redhead demon general, and the demon king's daughter. And it has some action, too. The appearance of the demon king is a bearded old man.