User blog comment:FairyRaven/Fairy Tail Chapter 437: Magnolia, Review and Commentary/@comment-5006572-20150525133532/@comment-9595671-20150525141756

They did the same with One Piece during the short time in returning to Sabody and then the beginning of the battle against the Fishman.

Showing power after a time skip isn't the easiest thing to do, especially since you need the characters to actually be stronger than various enemies or it will seem like they didn't get any stronger. Its a hard formula to get right despite how many series have used it.