i REALLY enjoy a "you brought this on yourselves" type narrative arc (and then imagine factions within the society who have like... convinced themselves that the corruption is good/holy/something to be worshipped so then there's also internal conflict potentially). and kind of love the idea of it as a struggle where the land is imbued with enough magic and/or sentience that its answer is to purge the land and punish the people
that would be GREAT. i'm imagining this as the weirdest collection of people who set out together without any idea what to expect so i could EASILY picture them getting split up or lost along the way