So do I understand correctly that you... don't know either?
Btw, while we're talking, I am curious about your Architect/Corypheus fascination. Would you care to explain?
I was just offering up what primitive scraps of clues I had.
I have that vague theory, but that's all, I'm afraid.
So yes. 
The Architect has a very alien mindset that's fascinating to witness. He's simultaneously a gentleman and a monster, and the contrast between the two makes all of his scenes in The Calling and Awakening that much more intriguing. When he's horrifying, he's horrifying on a higher scale than the typical darkspawn, because we only expect savagery from normal darkspawn. He reminds me of the Vord Queen in Codex Alera. A monster honestly trying to be human but failing in spectacular fashion to mimic us just wigs me out, personally.
And yet, he's an ancient darkspawn magister trying to save the world from his own mistakes, knowingly or not. He's utterly ruthless, but with noble goals. Debating the righteousness of characters like that against myself is, as the saying goes, 'my jam'. 
Jamie Glover's phenomenal voice-acting and the fabulous character design doesn't hurt either.
Corypheus proved to be shockingly sympathetic, while still being a complete (and kind of literal) asshat. This is an ancient sorcerer of Tevinter. He was High Priest of Dumat, the most powerful of the Old Gods. But their place in Tevinter society was evidently being eroded. So they got together, and they broke into the very heavens for aid.
And instead of their gods, they found power that nearly ended the world.
There's a very powerful story there, one I find much more compelling than the Chantry version of the Maker just casting them down in anger. Solas is lonely because he quite likely cast his brethren into imprisonment for their own well-being, and the safety of Thedas. Corypheus is lonely and betrayed because his faith has been shattered. He built his life around Dumat and the Imperium. And not only did it backfire in his wonky face, but he woke up in a world where the Imperium that was his world was just a pathetic shell, the sort of tired, bleeding empire he would have sunk below the earth back in the day.
So he goes a little crazy. He's determined that this world deserves a god, a god that answers their phone calls and actually lives in the goddamn Golden City like they were told. Corypheus genuinely seems to think he's helping the world by 'restoring' it to that theocratic Tevinter vision of Thedas, rather than the Magocracy with mysterious and absent gods that it seemed to end up being.
And again, David Sterne did some powerful voice-acting, and Corypheus's word-choice was often delightfully poetic.
Add in to all of this that I grew up enthralled by stories of Rome. More specifically, the stories of those who fought desperately against the odds to prevent the Empire from dying. As much as I adore Scipio Africanus and Cinncinatus, there's something so moving about men like Flavius Aetius, deadset on keeping the old wolf from dying of a thousand wounds. (Yes I did just re-watch the Attila trailer.
) And I love wizards and magic, and dark wizards who have more nuance than 'cackling old man, possibly on demon-meth'. And the darkspawn have always been a great, nightmarish foe.