Spoiler: Inconsistency between Bahamut and the 3.56 reveals

[Torquil]

Bahamut's rampage also changed the shape of the continent. Coerthas's climate changed, The West Shroud was annihilated, massive clusters of corrupt crystals could be found throughout Eorzea, Carteneau is in ruins, and the landmarks from 1.0 were either massively changed or destroyed.

Keep in mind that a lot of what you cite here was caused more by the destruction of Dalamud than by Bahamut directly.

[Berethos]

Keep in mind that a lot of what you cite here was caused more by the destruction of Dalamud than by Bahamut directly.

Seems mostly even - Coerthas entering a sudden ice age, afaik, doesn't have a set moment for when it happened (other than during the events of the Calamity itself as a whole), so it could be a mix of both events completely disrupting the aether (though given that it's a disruption of aether I'm personally inclined to give the edge here to Bahamut's attacks). The West Shroud we can't directly see. The massive clusters usually surround giant pieces of Dalamud, so that's an easy one to factor in.

Ultimately, while a lot of Dalamud's pieces rained down (in a particularly violent manner) on numerous areas, Bahamut sent out an incredibly large amount of attacks himself, and just a few of those landing in one area seemed to hit pretty hard, which could certainly account for the West Shroud's destruction and the various violence the land itself went through that changed or destroyed the landmarks of 1.0.

With Carteneau itself, that looks like a 1-2-3 punch...first Dalamud's pieces that got flung straight down/sharp angle down, then Bahamut's stream of attacks, then his giant fireball. It was probably in ruins pretty much after the first one, but the next two certainly contributed to the overall destruction...

Which is probably true of most areas hit, to be fair, and why I'm inclined to say the destruction caused was a more even affair (though I'm personally giving the edge to Bahamut...rewatched it and that is a lot of attacks he rains down in a lot of areas).