User blog comment:BlackWizardZeref/Fairy Tail Zero Chapter 10: Law Review/@comment-24039250-20150416231808/@comment-24039250-20150417022624

Who knows. Originally we thought that it was Fairy Magic. Now we know better. Zeref taught it to her. It's still possible that he created it as well. Also it was said to be Ancient Magic.....Zeref is more than 400 years old...I'd say he qualifies as Ancient.