Short inteview with Alexis Kennedy

Yeah I'd say the Mortalitasi are the super goth faction too.
Watching and worshipping the dead, and caring mostly about the dead and building them places...

The mortalitasi are a mage faction of Nevarra if memory serve, there are one of the rare mages faction who had power ( as in some direct political power in their own country) in Southern Thedas. At least before the breach.

Tevinter, Mortalitasi, Legion of the Dead... I'm good with any and all of the above.

It could still be the Kal-Sharok dwarves. There is definitely meant to be something odd about them. They are shorter and paler then Orzammar dwarves, give those who trade with them sinister vibes and very protective of their privacy. So they could have developed a death cult mentality that enabled them to survive in isolation.

However, I agree that the Mortalitasi do sound a more obvious fit. The order was originally founded by a Tevinter mage working with the first King Casper Pentaghast so it wouldn't be surprising for them to have strong links with Tevinter and also possibly access to ancient lore in their archives that was forgotten or erased in Tevinter proper. Also, I do wonder if the skills of the Necromancers were originally taught to them by followers of Falon'Din, elven god of the dead.

Which brings to mind another faction that could be a possible fit; the elves of the Tirashan with their blood red vallaslin and offering up of their opponents as a sacrifice to their god(s).

I wonder if there could be any sort of connection between the Kal-Sharok dwarves and the elves of the Tirashan? After all there was some sort of link in the past between dwarves and elves. Kal-Sharok were responsible for wiping out Cad'Halash for sheltering elves from Arlathan Forest and it was assumed this was because they were afraid that doing so would jeopardise the relationship with Tevinter. But what if the reason had nothing to do with the alliance with Tevinter but rather an alliance with the elves of the Tirashan? Then after Kal-Sharok was cut off from Orzammar may be it was the connection to the surface via the elves of the Tirashan that enabled them to survive. Kal-Sharok is located in the same mountain range and they had to have been getting supplies from somewhere. Allegedly it was only discovered they had even survived in the Dragon Age, yet it would seem there was evidence they had been trading with the surface, so unless Tevinter were playing a very secretive game with the Ambassadoria, their link with the outside world had to have been elsewhere.

Whilst I am a fan of all things elven, I would actually like more now for the other races. Another thought I was having, what if the Kal-Sharok dwarves discovered red lyrium long before it became known in the south? What if exposure to it had built up a resistance to its mind debilitating effects but at the expense of physical appearance? What if they had also discovered how you can "grow" it and so are farming it down below using their own people (may be criminals) as fertiliser or even people captured from the surface? Then it was weapons and structures forged from this substance that enabled them to resist the darkspawn for so long. That might account for why they are so protective of their privacy.