I'm working on a new setting where the entire mortal world is exactly on the border between the Astral Sea and the Elemental Chaos. As you can imagine, that causes a bit of tension when it comes to the Dawn War. I'm not that fond of the trend with D&D settings presenting the Dawn War as a cosmic war between two concepts, like Order and Chaos. Primordials are obviously chaotic, but the gods are very clearly not Orderly, at least half of them have the Chaotic lable stapled on them.

To subvert this a bit, I've replaced the Gods in the Dawn War with another group I'm calling the Eternals for now. These are entities of the Astral Plane that are totally static. They never change, always stay the same (Tharizdun being the only example so far, representing the eternal stagnation of a dead world), while the Primordials represent change. After X millenia of Dawn War, the Eternals tried creating the Gods as their soldiers. Long story short, the Gods overthrew the primordials, stuck Tharizdun in his own pocked universe, struck a deal with whatever Primordials remained, and created mortals.

What do you think?

(Also, since I plan to use Atropus as a villain, I'll most likely have him as some undead Eternal or an unholy cross between an Eternal and Primordial)

So I see you wrote this several years ago, but I was looking for some events to use in my version of the Dawn War and came across your post.

I've been heavily intrenched in writing my world lore and currently fleshing out the Dawn War.  I also have the idea of my world being between elemental chaos and the astral sea.  This actually explains much of the Dawn War occurs there as it is to be the outpost from which Tharizdun  planned to lead his forces against the universe.  It seems we have some similar issues on the idea of chaotic gods, but I have solved for this in my world.

I did a couple tweaks to the idea of alignment and introduce the concept of purity and corruption.  I have Ao being the essence of order given form and Azatoth the essence of chaos given from.  In my universe Ao forms and separates the essence of chaos into a separate universe (The Far Realm).  There Azathoth and all the other aberrations and Lovecraftian entities form.  All the my cosmic battles such as the Dawn War come from the idea that Obyriths from the far realm cut into the universe with the shard of pure evil which begins spreading the essence of corruption across the universe.  This leads to the War of Light and Dark, The Dawn War and every other conflict basically.  I basically establish that gods have divine essence of Ao and although the can be corrupted they still have an essence of purity within them.  On the other hand elder evils and the like are opposite and are purely chaotic.  It's a bit more complicated as I establish the difference from pure chaos and chaotic.  Essentially though I solve the problem of gods being chaotic by explaining a new alignment system based corruption.  The evil gods started at various stages of corruption with the first ones being pure in the beginning.  Corruption spreads like a disease so when fighting evil gods can become corrupted by it.  I go in to detail about the nature of divinity and corruption.  I also establish that dawn war primordials are corrupted by Tharizdun, except for some that Ao granted divine essence to for them contributing to creation.

By the way, I also have plans for Atropus.  I have the idea of taking all the star or planet like elder evils and having them emerge from the far realm at a later date.  It is basically Dawn War part two but instead of primordials I use a ton of Lovecraftian entities.  Again this is started by Tharizdun.