Hfhfdgdg said:
a mountain busting attack is 100~1,000 MT of force. If Acnologia is Large Mountain or Small Island in durability (being able to tank attacks that range from 1 and 4.3 GT), then ofc a mountain level attack would have little effect. He could still be mountain level (at the high end) and be able to shrug off an attack that is only a fraction compared to his durability.
He can't be Island if Igneel is mountain ESPECIALLY since IGNEEL WOUNDED HIM. They are both very likely to be within the same section in a tier with Acnologia being somewhat superior.
Acnologia has not shown anything to make him stronger than Large Mountain/high 7-A in dragon form. It does not matter if he one shot Serena. Serena is likely only 7-B since he still took damage from the 4 Wizard Saints and required two of his most powerful spells to incapacitate them when they were already injured.
Acnologia is likely only 7-A in human form AT BEST and high 7-A in Dragon form.
As i said, it's entirely possible that Igneel's melee attacks are stronger than his ranged ones. Also, it's not news to anyone that FT characters use magic to make themselves stronger physically. Maybe he just used more magic power when he ripped Acno's arm off than when he used that mountain-busting attack.
Yes, God Serena is likely 7-B. However, he did NOT take damage from the 4 Wizard Saints, at all. And when was it mentioned that those were his most powerful attacks? They were pretty basic, not even Secret Dragonslayer Techniques that every decent Dragonslayer knows how to use. Now, if he had used any SDTs, then you could say it took him some of his most powerful spells.