Quote Originally Posted by Anonymoose View Post
So where did the Amdapori Sin Eater images come from, if indeed that is what they are? Has the First been falling for 2,000 straight years? Did another dimension once come back from the brink and some sin eaters escaped? Did another dimension once fall and some sin eaters crossed over during that time? Did Amdapori inherit stories from the Allagans who somehow had knowledge of the sin eaters? Is this tied to the existence of the Crystal Tower? Are time shenanigans involved?
I think the simplest (and thus least interesting) answer is basically "timey-wimey shenanigans", because if you assume that time on the First passes at the same rate as time on the Source (at least in general), then everything breaks down.

The 3.x Warriors of Darkness supposedly caused their world to tip too far into the Light through their actions, including killing the Ascian of the First, Mitron. For this to actually have an effect, it would imply that Mitron was perma-killed, rather than having his essence yeeted out of his host like we did with Lahabrea and Thancred.

In the 2.5 ending cutscene, we see Elidibus warn Lahabrea that never before has an Ascian (or at least "that which is eternal") been perma-killed, in reference to our destruction of Nabriales. Lahabrea dismisses this in his arrogance. (But then what of Emmerololth?)

Later, in the 3.0 ending cutscene, Elidibus is on apparently the moon, and chats with the Arbert, Warrior of Darkness. So by that time, Arbert had already come to the Source.

So Mitron should have been killed sometime during the base Heavensward story, and the Flood of Light starting then, and Arbert and co. choosing the drastic measure of forcing a Rejoining, all in the span of time that Heavensward took, or at least maybe immediately after 2.5 (and before 2.55) and immediately before the scene on the alleged moon.

Which, as far as I can vaguely recall, is something like a couple of months? Subject to the time bubble of the Source, of course.

I can't see any way around this other than "well, time flows differently", which will in itself cause shenanigans when we have to move back and forth between the First and the Source (due to player convenience reasons).