There was some speculation as to whether or not their thoughts could be shared with the spirit of the deceased person taking over control. The spell had been used successfully so infrequently in the past that there weren't enough examples to understand it fully. The very idea of only being able to interact with Bellatrix inside her mind filled Hermione with indescribable fear and horror. While she certainly deserved to pay for all of the terrible crimes she'd committed over the previous twenty years, that fate sounded worse than a thousand days locked in a side-room on Level Eleven with Rabastan. Death of her body would be her only escape from her prison and she wouldn't even have the ability to kill herself if she so desired.