Now I've seen the Godbound rpg compared to White Wolf's 1st & 2nd Edition Exalted rpg systems respectively. Yes it shares many influences from both of those games but its got more in common with other OSR & old school rpg systems then simply Exalted. Yes, the Kevin Crawford has infact cited those two editions of the Exalted games as influences.
What's this got to do with the Arduin Rpg books & Cha'alt? Well a bit of everything because the minute that you turn your Godbound onto the campaign setting & dungeon that you've created they might be in real trouble!
There are 21 Hells in Arduin each of which is a different dead planet on a plane of damnation. Some of the single most dangerous old school demons come from hallow pages of Arduin. Even with some of the most verstile words & miracles a party of Godbound PC's might well run out of steam long before they can take on these sorts of demons. It would take an experienced party of Godbound to take on a wind demon.
The mega dungeons of Cha'alt are another matter entirely as the PC's might well have to go above & beyond here. The reason I say this is because the dark gods of the Black Pyramids have their own alien agendas that Venger makes crystal clear. The gods of Cha'alt want to bring back to power their own unlife existence. There's a machine at work within the confines of the adventure of Cha'alt. Could the black pyramid have its own unearthly agenda? Absolutely it could!
We're not talking subtle monters but engines of destruction on a very large city scale form of destruction. This goes all of the way back to the halcyon days of 1977. Destruction & corruption is the name of the game on a grand scale. If you haven't grabbed the free Swords & Wizardry book Ruins of Arduin then I strongly suggest that you do.
My point is that if your going to run a campaign using gods then demons are a good choice for enemies & foes. I've personally seen this sort of a situation using the Castles & Crusades rpg system several times. Demons of the Advanced Dungeons & Dragons variety are incredidbly powerful & can be mini gods within their own right. They have cults, a wide variety of powers, lots of abilities including shape shifting, & even influence on the mortal realm not to mention the backing of the infinite layers of the Abyss. The Abyss is the planar glue that often seems to hold the layers of the various Hells together. Demons can be vary subtle though. Often it seems to me that many old school dungeon masters think of demons merely as blunt trauma monster hammers.
In fact if we crack open Mayfair Games Demons II box set we see an alternative set of subtle & very dangerous infernal monsters. These things used correctly can torture even gods & demigods. But the dungeon master must understand the care & feeding of these demonic horrors.
Demons have to be used in a round about way subtly corrupting, causing chaos, & using every trick in the book and after life to discredit, corrupt, tempt, & lead entire teams of players down the rocky path of Hell.