User blog comment:Emillianna/What is Lumen Histoire?/@comment-204.10.221.143-20140502114551/@comment-76.124.155.27-20140502232347

I think Zeref crated Fairytail and was overcome with darkness either by being infected by a demon or the magic he needed to complete a certain task warped him and Mavis went on to be the official 1st guild master. With that being said I think it's an anti-demon magic that Zeref left for fairytail.