I have never seen a "make a person a zombie" spell.
By that I mean to say a love spell will not make someone love you that is not capable of loving you nor will it control them.
It is always better to work with finding a person, and not attempting to cast a spell on a specific person. Largely because of the reasons I stated above.
Conscious thought vs higherself. It is possible to connect with the higherself of someone. In some instances the higherself might make decisions for the self without the self actually knowing. But there wont be a removal of free will due to magic.