fate of emperor varis at the end

[Iscah]

We've already seen what can happen when the scales tip too far in favor of Light. What's more, it is implied on multiple occasions that the Source was headed for the same fate because of the Warrior of Light. While we can't ascertain whether or not it was intentional, it does appear Hydaelyn was putting the Source at risk by constantly compelling her champion to fight.

I think those implications that "Hydaelyn's command to fight the Ascians is putting the Source at risk" were a result of what we previously understood from the WoD arc: they killed the Ascian overlord of their world and triggered the flood, therefore if we did the same thing here, the same thing would happen.

The truth as shown in Shadowbringers is considerably different. The flood and the imbalance that caused it were due to Ascian meddling in the first place, and the balance tipped over the edge because they failed to account for how Ardbert would react.

The destabilising of aether on the Source was due to the Ascians meddling on the First, not a disconnected sign that something was wrong with the Source because of our heroic actions.

Perhaps most importantly, the Ascians aren't some supernatural embodiment of Darkness (as we might have previously assumed), without which the world will be overrun by Light. They're just people, in the end, however powerful they are.