User blog comment:IamJakuhoRaikoben/Chapter 449: Mavis & Zeref, Review./@comment-4933386-20150824131731/@comment-112.200.65.240-20150824144134

Uhm.. Mavis just used "Law", not Fairy Law. I think she kinda revised the magic so she won't harm anyone with it. Like what Precht did.