User blog comment:FairyRaven/Fairy Tail Chapter 377, 378: The Sky Dragon's Rage & Friends Forever, Review and Commentary/@comment-83.255.207.11-20140328095434/@comment-5593752-20140328095756

I reckon it was supposed to wipe out all magic as they thought, but due to Wendy damaging it the effects won't be as severe. Like perhaps all wizards will lose half their magic power or so