I need an Umbral Calamity refresher as Dawntrail has me confused

[Alenore]

In all sincerity, the way the game presents the "facts" or the history of the shard of Alexandria is messy, but... it just makes for a really weird "coincidence" to have a non-rejoining "end of the world" happen in a shard. I am very sure that the NPCs both in Everkeep and Living Memory say it pretty explicitly that everything outside of the bubble got absolutely vaporized. It is like every beat of the rejoining process is repeated, but actually this time is just a coincidence. That we get a planet that is overflowed into a single aether element, that then is goaded into a war, that then has its "Wave of X" even. We get that reference directly in a dialog choice from us, they have so many things spotlighting it. And what, it just failed? Is it a Void thing where if you fly your mount outside of the Living Memory, there is just a whole planet of purple thunder goo everywhere? Or just a barren rock?

In all honesty, how the game presents it, you are meant to assume the shard got rejoined. It would be a weird for the expansion to so heavily play on that and then suddenly just switch it up. That is how I feel about it.

Ascian methodology is literally creating an aetheric imbalance so that it would break the world between dimensions so they're pulled back in the Source. We know they have been messing with shards to prime them for Rejoining at least as early as when the Void was created, so at the very minimum before Allag (I don't think we have mentions of Voidsent before that?), so a Shard being close to a calamity state isn't a stretch at all. They're most likely all already somewhat unbalanced and near the tipping point to be merged if the occasion presents itself on the Source. Black Rose succeeded in fucking up the Source in an alternate timeline.

The lightning devastation on the continent was triggerd by Lindblum's superweapon. It was described as engulfing the continent, not the whole world. Not sure how Alexandria would know that, though.
Either it was an Ascian plan, or Lindblum went overboard with it and just caused widespread mass destruction. It's not unheard of: Koryu almost caused a mass destruction event on the Source, unrelated to any Ascian plot as far as we know.

I'm not sure where you gathered that the rest of the world was vaporized, but Sphene says in one of the first quest in Heritage Found that they had no idea what happened outside of the dome before Zoraal Ja went through. If you have a specific NPC dialog or quest mentioning it, I'm very interested, that might put things in a new light.

However, I disagree that the game makes you assume the shard got rejoined:

• Y'shotla directly mentions it leads to one of the Reflection ;
• We're told since the beginning that rejoined Reflections are totally gone ;
• At no point do they speculate it could be a rejoined shard, and all Scions know that one shard fell to lightning ;
• The interdimensional fusion is described as being able to merge a reflection with another, not drifting part of land in the interdimensional rift ;

They actually make sure you understand it's not one of them. The only link is Lightning, and since there's only 6 elements plus Light / Darkness, they will obviously overlap at some point.