I like the adventure premise, ash covered and demon infested land. But as others pointed out it seems to miss a clear resolution and has incomplete tables.

It's an interesting scenario, but it doesn't seem finished. The ashrot and warplight tables are incomplete. That, and there doesn't seem to be a clear objective or conclusion. How are the players supposed to banish the demons and stop this disaster? You would be hard pressed to run this if the players are dropped into this scenario without some idea of what to do to resolve it.

i like the idea of an ash-covered landscape and the first two warplight mutations are spooky. probably could have found a way to explain weather, ashrot, and warplight into fewer pages. it would be great to use that space for dungeon maps of the tower, citadel, and library. even more important might be the inclusion of some factions to help show the story and offer some alternative routes. the knaves may wish to try you on that "no escape" thing if they can't see others drowning or rebuffed by a big wall. some good ideas here that would benefit from some additional time.

Great choice of illustrations for the City of Gallvant and the Equipment & Relics pages. The Everburning Library is an awesome portent to the end of civilization.

I think the Ashrot Maladies table might have the wrong content in it.