Dullahans counteract the cons since they can put their real heads off to the side and stick the fake head right on their neck, and they are already adept at moving with their heads off to the side.
When we thought that tree jizzing all over a city and gender bending sirens were was odd, the author give us vore mating...
I wont be surprised if in the future there is a chapter were there must be a dancing ritual before they do it.