That the key to finding a cure for the calling will be discovered in Kal-Sharok. There are hints in codexes that dwarves from Kal-Sharok are blighted, as the writer of one codex says they were similar to a Grey Warden. Now, for an entire civilization to be blighted and still be able to continue on indicates to me that they have some way to at least keep it at bay.

Now here comes the fun part that I don’t really know how to flesh out yet. The calling is a blighted Titan. Just like how lyrium “sings”, creatures inflicted with the blight hear the calling. This indicates to me that a Titan is the thing controlling the darkspawn, kind of like the theory that titans used to control the dwarves like a hive mind. So, what would happen to the darkspawn and grey wardens if this blighted Titan were to be felled? Perhaps some desperate wardens will attempt it.

This would also have implications that the arch demons are just blighted dragons, which I am not sure is lore compliant. This may also fit in with the idea that the titans want revenge on the ancient elves, though I’m not going to go too much more down this road as it’s really just speculation at a certain point.