User blog comment:IamJakuhoRaikoben/Chapter 447: Escape Battle, Review./@comment-26451407-20150805081453/@comment-1153699-20150805182016

Gildarts was stated to be on GMG Jura's level. If he didn't train and just decided to travel and do whatever he feels like doing during the past year, then yeah, 100%.

In fact, I think Natsu has already surpassed Gildarts. Possibly Gray, Erza and Gajeel as well.