It's not a retcon. A retcon is when the author purposely nerfs and Mashima didn't do that. She can match Erza offensively but is outclassed everywhere else. What made Erza match Laxus was stats like endurance and such. In terms of offensive power, Laxus is far ahead.
Yes, that just means that Elfman has something stronger than a FDK Demo Fist which is Natsu's weakest FDK attack.
Acno is arguably already surpassed and Zeref was never the strongest so what's the point and even then, he was surpassed for a brief moment by Natsu. Spriggans have already been surpassed. You have to wait for more enemies to show. Diabolos > Spriggans (aside from Irene and August) and who's to say anything about Georg or Suzaku.
Hades was surpassed by the next main villain which was MG who was surpassed by the Spriggans. It very much is a pattern that's working.
He wasn't struggling, he was caught off guard. Two seconds later he literally laughs it off and ends it.
I do believe he did retcon, by your standards as well. See how the DE fared in R1 and R2.
Round 1:
- Madmole took no damage from Natsu's FDK demo fist. Natsu had to resort to heat to damage Madmole
- Kyria, without her hax, was giving Erza trouble
- It was implied that Skullion would've rekt Gray with his black ash or something
Round 2:
- Madmole stalemate with Elfman, and Elfman is only capable of physical attacks
- Kyria got no/low diff'd by Laxus
- Skullion stalemate with Mira
You say Elfman had something stronger than FDK demo fist? WTF? Demo fist is one of his strongest attack.
See FDK demo fist moves Natsu used in the main series. The final one was in DF tho, but anyway it managed to completely vapourize FH Zeref's body (point is that this is indicative of demo fist's power without his DF, but that Natsu regards it as one of his strongest moves and finisher)
This is Natsu's Demo fist in spin off, almost vaping an entire city:
You expect me to believe that Elfman, who is below base Natsu, is capable of generating an attack far superior to Natsu's FDK demo fist (yes, it has to be far superior, because Madmole comfortably tanked it, clearly Madmole's limit is far higher than Natsu's FDK attack)? Yea no, I'm not buying that.
Now, you say Kyria can match Erza in attack power. But, she failed to put even a scratch on Laxus the entire fight. Her roar also failed to put a scratch on Laxus and Jellol as well.
Either Erza would've failed to scratch Laxus as well if not for dragon seal and Natsu/Gray swords. Or it's a retcon of Kyria's powers. Because if this is the extend of Erza's attack power (w/o dragon seal and Natsu/Gray swords), then it doesn't matter if her dura is super high compared to Kyria, she still won't be able to scratch Laxus.
Mira stalemated Skullion. It was at least implied that Skullion would've low diff'd DeS Gray. I don't see Mira low diffing Gray, hell I don't see even Laxus low diffing Gray. Even Laxus would need mid diff to beat DeS mode Gray
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Acno isn't surpassed yet IMO.
Zeref is still the 2nd strongest human (1st being Natsu). No villain so far has surpassed him.
Hades with GH might be able to beat Mard. But it isn't the point. Mard was the main villain of the arc, I already agreed to main villains surpassing main villains, and mini villains surpassing mini villains. But mini boss surpassing main boss? Not necessarily. Hades in his base itself is GOI tier, you think he won't be Spriggan tier after jumping multiple tiers from Grimoire Heart and Devil's eye?
No, I don't think the Diabolos members we've seen so far can beat most Spriggans. For eg, do you see Kyria beating Dimaria? (so, even the trope of mini boss surpassing mini boss isn't happening here). As from Black dragon eaters and guild master, yes, I fully expect them to, but we'll see.
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Yes, and Natsu then claim that Makarov was way stronger. And Natsu ended it with a FDK demo fist, not some fodder spell. And like I said before, Makarov is still used as a benchmark to show characters as "strong". In Alverez arc, and in spin off. "Makarov level" hasn't become irrelevant yet.