User blog comment:Omega natsu2/Chapter 413: The Book of E.N.D., Predictions./@comment-9595671-20141211045655/@comment-7418318-20141211102756

I wonder if maybe they got Grandeeney to do the memory manipulation for them. With her possessing telepathy, it wouldn't be that much of a leap to have her able to use that magic too.

Come to think of it, having both memory manipulation and telepathy seems a good combo to me, since you can "look inside the target's head" to make the fake memories fit flawlessly into their real knowledge, while having only memory manipulation can result in messups like "Mest" did.