The Kingdom is fairly religiously tolerant. I mention a common religion among the aristocracy under the faction section that's sortve the defacto state religion/religion of much of the human aristocracy. It is loosely confuciany in flavor, but it's not exclusive of other religions and it's not an established church or cult. You can feel free to make up common/powerful religions in the Kingdom though! I'd rather stay away from 'repressive medieval church in space', but otherwise go hog wild!