I was just sitting there thinking about red lyrium, and about how Bianca said that this is regular lyrium that carries the Blight. But then I remembered something from Dragon Age II that suddenly blows the top off of everything we thought we knew about the blight. The Primeval Thaig containing the red lyrium idol had already been lost at the height of the Dwarven Empire, which was prior to the First Blight.
The blighted idol predates darkspawn.
At first, I thought maybe it was regular lyrium that was later corrupted, but Inquisition confirms that the Primeval Thaig’s inhabitants were corrupted by the red lyrium prior to both the Dwarven Empire and the First Blight.
What if the Blight came from the Dwarves, not the magisters?
And with this in mind, I remembered two other important facts: Dwarves can’t use magic (are not connected to the Fade), and yet certain things inside the Primeval Thaig could have only been created by magic. We all took for granted that dwarves are specifically stated to not be disconnected from the Fade, and there has to be a reason for this. Especially with the heavy hints that once it had been otherwise.
Remember what Corypheus said about entering the Golden City?
When they arrived, the City was already corrupted.
Red lyrium predating the Blight. The dwarves severed from the Fade. The Golden City corrupted before the magisters’ arrival.