User blog comment:IamJakuhoRaikoben/Chapter 449: Mavis & Zeref, Review./@comment-174.25.44.24-20150825014908/@comment-24546844-20150825020151

Mavis knew about Ankseram curse so it's probable that other people had already been affected by it so the curse is probably always the same. The problem is, if there's a way to know the curse it's because someone who's been cursed before registered it. This person is either an immortal walking around like Zeref or found a way to die thus there's a way to get rid of it without creating a super powerfull demon who'll probably erase the life on earth. Maybe summoning and making a deal with Ankseram himself.