User blog comment:LegerPrime/Natsu vs. Acnologia/@comment-153.91.238.254-20151012183713/@comment-25572451-20151014212827

@Anon at the end of the day it's all speculation since we never really got to see what either of them did for training during the timeskip. For all we know Gildarts could have been in Alvarez at some point gathering intel, but like i said we can only speculate. It's just safe to assume that all the characters got stronger over time because that's how these shows work, the only exception would probably be makarov since it seems like his skills are in freefall due to his age, but again that's speculation as well. only way we know or not is by seeing them fight in the upcoming chapters