Rejoining question SPOILERS

[Edax]

The First is naturally strong in Light aether.
Before Loghrif and Emet came to the First, there was no prominent Warrior of Light, and if there was, none of them have won over the Darkness enough make the First in the situation of a Rejoining or a Flood.

It was Loghrif and Emet plan to create the strongest Warriors of Light of the First, making them have success against their minions, and by doing that making the Light stronger in the balance with the Darkness.

The end should have been to kill their last and most powerful servant, creating the ideal situation for a Rejoining.
But by killing Loghrif instead, an Ascian that is more or less Darkness incarnate, they basically won too much, breaking the balance entirely, in a world where the Light is already too strong, provoking the Flood.

I still don't quite understand, Ascians aren't native to the First so why would their life or death have any connection to the alignment of the First? If the source Warrior of Light was defeated and became a sin eater, would the First get "darker" as a result?

[Iscah]

I still don't quite understand, Ascians aren't native to the First so why would their life or death have any connection to the alignment of the First? If the source Warrior of Light was defeated and became a sin eater, would the First get "darker" as a result?

Our earlier theories (pre-Shadowbringers) were based on Ardbert's understanding that killing the Ascians directly caused the Flood - and because of that we assumed that Ascians must be 'cosmically aligned' to Darkness and keeping the balance. That information is outdated now.

I haven't actually got to the final role quest yet so I'm going on why I've heard from others, but my understanding is that killing Ascians (who we now know to be "just people", if extremely powerful ones) isn't inherently a problem - but killing the person carefully manipulating the balance of Light and Dark without being aware of what they were doing, and especially just after you've altered the balance in a direction they didn't anticipate, is going to cause that plan to fail and the careful balance to tip, and suddenly the world is in a Flood state it was never supposed to actually reach.

[Zackneifein]

Our earlier theories (pre-Shadowbringers) were based on Ardbert's understanding that killing the Ascians directly caused the Flood - and because of that we assumed that Ascians must be 'cosmically aligned' to Darkness and keeping the balance. That information is outdated now.

I haven't actually got to the final role quest yet so I'm going on why I've heard from others, but my understanding is that killing Ascians (who we now know to be "just people", if extremely powerful ones) isn't inherently a problem - but killing the person carefully manipulating the balance of Light and Dark without being aware of what they were doing, and especially just after you've altered the balance in a direction they didn't anticipate, is going to cause that plan to fail and the careful balance to tip, and suddenly the world is in a Flood state it was never supposed to actually reach.

I still think that Ascian are "cosmically" aligned to the Darkness.

What we now know, is that Light and Darkness are more complicated than "Good and Evil".

But even if we are called Warrior of Darkness in the First, we still have the Benediciton of Light, we are Light aligned due to our connection to Hydaelyn who is aligned with Light (we also know that contrary to previous assumption, she isn't the Origin of the Light nor she have an absolute control over it).

Same for the Ascian, even more the Three unsundered Ascian that are tempered by Zordiark. They use Darkness power, call over the Darkness for their powers as much as over Zordiark.

Even at the end the fight with Hades, we are the "Light in the Dark" and the description of the buff clearly state that we are defying the Darkness by fighting Hades.