"Who, WHAT are you?" *main story spoilers*

[Tenkuu]

Because Lahabrea and Igeyorhm were using the Echo to violate Hydaelyn's laws in the first place...

... then we beat the shit outta the Ascian Prime...

So you're saying the power of their Echo got weaker?

We know nothing of real value about the Warriors of Darkness beyond one of their names (and we don't even know that in-story).

Morningstar1337's post reminded me that Y'shtola does comment on the Warriors of Darkness in 3.1, and in the Japanese version, as Fenral translated it in another thread, says:

感じたことのないエーテルね。テンパードにされているような感じはしないけれど……。
It's not like any aether I've felt before, but I don't get the feeling that he's been tempered...

So we do have at least some indication that Y'shtola considers them to be very strange and dangerous. Though in the Japanese version she omits her warning, her tone itself is cautious. We can imagine that the aether of a (former) Warrior of Light would change and feel so strange if he'd become a power hungry creature.

I'm hesitant to speculate about the Auracite because, unlike the people from lil' White's tale, we do not use it to trap and keep aetherial beings as aether batteries. That sounds suspiciously like what the Allagans did and the Garleans are trying to do... a possible source for a Kefkaesque descent into madness for Regula or Varis? Hmm...

So there are various types of Auracite, most likely, and the one we're using is a temporary variant. If not that, perhaps there are simply more advanced methods of using it and we just don't know about them. The thing is, unless Dalamud was made of, or at least comprised *some* Auracite, the Allagans seem to have used a different material and/or technology to trap Primals.

Before you are saying I am using this disparagingly, I would explain you that it is essentially what I did that entire paragraph.

First of all, I appreciate that. Second, I'm not exactly well versed in most movies (lack of interest), so I'm not even sure what that's from. Third, well, I was agreeing with you, just sort of expounding on it. Unless you feel that I just repeated what you were saying?