Charr Submarine? Speculation and Opinion
The DSD is already awake, so it wouldn’t be referring to its waking cataclysm – The DSD’s waking was unfelt by Tyria. But it could relate to the DSD’s intentions instead, a theory I’ve had.
Ascalon doesn’t have mountains to the north (well, not entirely at least); and to the north the Charr Homelands aka Blood Legion Homelands don’t have mountains to the east.
Charr submarines are a relatively new concept. The first prototype of a submarine is in Plains of Ashford – though we see several of its more completed designs later on such as in Mount Maelstrom and Straits of Devastation. The Black Citadel, however, is nearly two centuries old – so it’s unlikely to be intended to be a submarine.
Besides, it’s more of an orb – hence the oft old nickname of the Charr Star (from the Death Star, naturally).
Stop treating GW2 as a single story. Each Season and expansion should be their own story.