Seems like we've reached the usual "arc's weakest part" with this chapter... for 3 reasons:
1- Plot armor saves Wendy; I just hope she'll reveal a new ability during this battle.
2- As I expected a few chapters ago, plot armor saves Lucy. Is there any other explanation for the Diabolos duo to get from one end of this dragon to the other so fast?
3- Since I'm talking about those two, why are they both in a battlefield with no "dragons"? I understand that their priority seems to be getting rid of threats to their plan, but couldn't they start by scattering and going elsewhere, instead of both going after Lucy and the Strauss siblings? The Armor one could have gone after Gajeel, and the other after Gray. That would be smart enough, I guess?
BTW, I expect Erza's plan to fail almost immediately as Kiria notices her, forgets about Laxus for a few seconds and cuts the orb in half.