Therefore I don't think firmly committing Durge to one or two classes or playstyles is warranted, at least not yet.
Agreed. However, the cloak is called 'Deathstalker' something. Deathstalkers are/were priest-assassins from the Church of Bhaal. So, just going by that cloak; I'd say Trickery Cleric / Assassin. Not everyone's cup of tea in 5E. It's certainly not something you'd want to combine with what we've established as the canonical Sorcerer class. But, it is something I'll be running for either Durge or Shadowheart. Or both if it's super fun.
Having said all this, we don;t know how we *acquire* this cloak. Perhaps, if you go resist-the-Urge, you take it *off* a Deathstalker in your quest to rid yourself of the curse, or somesuch. Treasure doesn't define a character.
For me, personally, I think 'Canon Durge' is as much an Albino Dragonborn Sorcerer as 'Canon Abdel Adrien' is Gorion's Ward. There's no 'Canon Tav' either, just a default one being a Cleric of Selune. So far, anyway.
