User blog comment:Miskos3/Fairy Tail Chapter 506: The Broken Bond, Review/@comment-153.91.194.203-20161017213839/@comment-5303512-20161018030132

Few things wrong with that:

1. Natsu and Gray were never stated to be stronger than Erza post time skip.

2. Gray only won against a Spriggan because that Spriggan was Invel, that means he was in the advantage compared to the other Spriggan. Ajeel or even Historia God Serena would have destroyed him.

3. Natsu was clearly not handling his new powers at their fullest and thus was not that strong in comparison.

4. Erza had been incredibly strong since he debut, Natsu and Gray have known her strength and both feared and respected her.

5. Both Gray and Natsu were tired while Erza while slightly injured is still fresh for a fight.