"What will happen to my father's soul and body? Do you plan to start living as my family?" Regina asked.
"If you try staying in a body that does not belong to you, you will lose yourself and go on a rampage attacking humans. Is that the kind of life you want for yourself and your family? With all the souls tied to this house being freed, Grimms will start to show up to lead them from this world. It won't end well for your souls in the underworld if they find you in this body," Auror explained to the soul.
Aurora knew about this from her time at Artemis's side. The night Goddess was good friends with the devil and had a lot of information about the underworld.