User blog comment:IamJakuhoRaikoben/Chapter 449: Mavis & Zeref, Review./@comment-4933386-20150824131731/@comment-24367018-20150824164056

I had a thought not that long ago that the way Fairy Heart worked was that it 'cursed' anyone bearing the Fairy Tail crest with immortality in a similar sense to how the Tenrou Tree did.