Garlemald's situation. (Spoilers 6.55)

[Cilia]

As I said earlier, the Garleans have been using ceruleum for centuries - extracting it right out from under their feet, maybe refining it, maybe not - with no visible negative consequences to their home territory. It's not known to have any adverse effects on the environment (other than the blue haze that comes with its extraction... sometimes), it's not mutagenic, and it doesn't deplete the Lifestream like Mako energy does. All aether eventually returns to the land, to be reused in the great cycle.

... [Y]ou'd expect that a Darkness-aspected calamity might make ceruleum even more volatile, to the point of it being unusable as an aetheric energy source.

Maybe, maybe not. Could just supercharge the ceruleum, such as that it burns hotter / last longer.

Either way, not an issue since the Seventh Calamity's destructive effect(s) were heavily mitigated by Louisoix's planning, and the writers probably didn't have that lore bit planned out during the Meteor Crisis that concluded 1.X lol.

[SannaR]

The issue around ceruleum need not be an 'environmental' issue in the strict sense of the word. Bloodletting the lifestream as an energy source probably has some sort of detrimental impact on the star, even if nobody is aware of the consequences yet.

It will create an issue around Island Sanctuary if this ends up being a plot point, though, because the final upgrade seemingly converts everything to ceruleum power.

I don't think the last upgrade is meant to be cerulean since it's meant to be running off of whatever they're using in Labyrinthos as fuel. Since that upgrade goes along with Moenbryda's parents and Puddingway. We only are meant to get Jullus and friends after you've gotten past the point where he and the other Garleans tell the twins to go on a Vacation.

[Lyth]

The Seventh Umbral Calamity strikes me as an unusual case compared to the rest. The EE Volume 3 uses the word 'Astral' to describe the rejoining experienced by the Seventh, which is used to describe a polarity using the terminology of the Source rather than an aspect. You can have unaspected aether with an astral polarity, for example. I'm aware of the connection between the astral aspect and the darkness polarity, but it seems odd that there's no description of a corresponding 'Flood of Darkness' on the Seventh.

I was thinking more along the lines of what would happen if you dropped ceruleum into the Void, as an aetheric energy source.

I looked through the rank 19 cutscene, and I could see no specific reference to the fuel type used by the buildings. That strikes me as difficult to incorporate into a cutscene, and if I remember correctly, I don't think the upgrades were mandatory. Labyrinthos is mentioned in passing in the rank 19 scene, but only as a reference around how difficult it must have been to cultivate the area. Would you mind providing the specific quote that you're referencing in your claim?

[SannaR]

The Seventh Umbral Calamity strikes me as an unusual case compared to the rest. The EE Volume 3 uses the word 'Astral' to describe the rejoining experienced by the Seventh, which is used to describe a polarity using the terminology of the Source rather than an aspect. You can have unaspected aether with an astral polarity, for example. I'm aware of the connection between the astral aspect and the darkness polarity, but it seems odd that there's no description of a corresponding 'Flood of Darkness' on the Seventh.

I was thinking more along the lines of what would happen if you dropped ceruleum into the Void, as an aetheric energy source.

I looked through the rank 19 cutscene, and I could see no specific reference to the fuel type used by the buildings. That strikes me as difficult to incorporate into a cutscene, and if I remember correctly, I don't think the upgrades were mandatory. Labyrinthos is mentioned in passing in the rank 19 scene, but only as a reference around how difficult it must have been to cultivate the area. Would you mind providing the specific quote that you're referencing in your claim?

I don't have any quotes and even if each upgrade isn't mandatory each style matches those who visit. That and during the quest Once Forged we go and help G'Raha with increasing the amount of aether being directed to Kokkol's forge. Fire aspected aether is regulated in Labyrinthos by an elemental reactor. We also end up fighting an Anala while we are helping Verpaulaine figure out why Labyrinthos's sun isn't the correct hue. Once again only fire aspected aether is mentioned. As it's been eating on the fire aspected aether that's in the supply line in an area where it's fairly close to the surface of the ground. No mention of cerulean being used.

Again I know the visual looks aren't mandatory and can be changed yet the game expects you to do so. As they line up nicely with who you receive on your island after you've unlocked the new aesthetic. Rank 19 gives you buildings that look like the ones found in Sharlyean and you get two renowned Sharlyean researchers. Rank 15 gets you early Industrial Revolutionary looking buildings and unlocks the visit from Sicard and Emmanellain who shows up in the Baronial set attire. Which matches the building look and adds on to the strange (at least to me) insistence of Ishgard going down the Steampunk rabbit hole. Rank 12 doesn't have a different look, but does allow you access to the mountain hallow and the gamboling garden landmark. I guess to show possible progress of your island and the devs probably couldn't think of a look that said Azim Steppe since that's the visit you get Sadu and Cirina. Rank 9 being the first visit where you have two Lominsans visit on the same rank that you unlock the Lominsan Lighthouse landmark. They probably weren't thinking too much about coordinating the looks with the visitors in the initial launch and the first update set.