User blog comment:FairyRaven/Fairy Tail Chapter 392: You Must Not Forget, Review and Commentary/@comment-7418318-20140711094725/@comment-10058473-20140711164214

Could be something similar to Sayla's curse but that only works on the (un)dead.

Sayla's macro doesn't override the victims personality as seen with Elfman. It also doesn't stop her from acting on her own while controlling someone else.

And as said in above posts, the control may not be completely strict and allow some freedom if not under an order.