I don't know why everyone is thinking
'Golbez' is Azdaja, given he outright stated that he's been waiting for "ten thousand years" and he and his compatriots are clearly seeking redemption for their fallen world, where as Azdaja has only been trapped in the Void since Allag times (read, around 6000 years or so). It's obvious the Knight in Black and the Elemental Thrones are native residents of the Thirteenth, and are probably the fallen WoLs that caused the Flood of Darkness, not a dragon from the Source who arrived in there much later.
Also,
there is no good reason why a dragon like Azdaja would prefer to assume an armoured humanoid and very male shape in the Void even with the Darkness-induced aetherial warping going on, instead of maintaing a more draconian one. It's far more likely that Azdaja is going to appear somewhere else in a completely different context, and that the Knight in Black is Azem's Thirteenth soul fragment as I mentioned, as it makes better sense. Or the Knight is someone else entirelly.
Either way I don't think the Knight in Black is going to turn out to be Azdaja, as that idea just doesn't fit.