End of Book 11

I'm in the key rune we're Arthur meets the embodiment of fate and fate explains what the nature of the future is and what the indraths did to the civilization.

I may didn't understand that correctly

Why did the Indrath kill every civilization? Because they needed more aether in the atmosphere because they separated epheostus and that made the world lack aether?

And the end of the world the "nature" is it preventable? And is it just pure aether in the end?