All of this arc wouldn't be so ubber bs if:
-Natsu awakened his demon powers and dragon powers completely during the timeskip.
-We would have got a bit of info why Gildarts can't control his powers? Is it too great? Is he of a bloodline of great mages that are born with great power? I mean Hiro should at least have given him the title strongest of Ishgar and not such a pathetic fight against Bluenote.
-Wendy should have shown to be ablle to enchant DS on others before this arclike in an arc where actual dragons appeared (GMG).
-Erza should have never won the fight against Irene with only one arm functioning. Erza shouldn't have been so pressured by Ajeel who lost against freaking Lisanna and Elfman.
-Gray and Erza shouldn't have been so pressured by Brandish magical power if they a few days later went on to fight enemies way stronger than Brandish without being pressured by their magical power.
-Irene shouldn't have any link to the dragons. the whole story about her and the dragons is still bs especially since she and the dragons didn't think about enchanting weapons instead of humans with that magic like Wendy did.
-That FL uses up life-force should have been mentioned before. It's not like it was used for the first time.
-Hiro shouldn't have made Zeref say that Failcarde is his secret weapon for Acnologia. the guy couldn't even handle Sting.
-The GOI shouldn't have been OHKO'ed by one mage. I mean these people are near Laxus level so they should have been able to put up a fight against Serena.
Conclusion: This arc is full of failures due to Hiro always relying on last minute power-ups.