User blog comment:FairyRaven/Fairy Tail Chapter 401: Igneel vs. Acnologia, Review and Commentary/@comment-24467372-20140922162609/@comment-5303512-20140922192425

@ML, remember Gildarts said that when Fairy Tail becomes number 1 again, he would return. So there is a strong possibility of him returning. I seriously doubt that Gray can beat Mard Geer even with Extreme difficulty, it's like saying Natsu can defeat Acnologia on Extreme Difficulty. If you don't think Gildarts can match Mard then Fairy Tail is in major trouble.