User blog comment:IamJakuhoRaikoben/Chapter 298: The Breathtaking Land of Ryuuzetsu, Review./@comment-4829046-20120908023741/@comment-4829046-20120908024830

Good point but I doubt Elfman knows how to Mask Magical power. So far the only person who has been able to mask magical power and remain undetected by anyone is Zeref. Of course it is obvious that you can't tell "who's" magical power it is unless you know that person well.