Woah this one must be true, someone pranking homeowner by sticking paper doll with face on peephole but because its 3 am and homeowner still sleepy he saw that paper doll as himself
Maybe that parasite want her to be the dominant one, like he said before that when she wake she will have full body control. Its just that parasite moral code in my opinion
Sadly i think its pretty realistic in this story for her whole life she is a slave and always treated unfairly and maybe they always give the guardian duty to ability user so maybe thats why they immediately recruit her. And maybe this is also a form of protection for her from that SOB lord