I also believe the figures striding the storm are two of the Unmade. Patrick's theory on the alien and sleek one being Re-shephir makes a lot of sense. The other figure however is harder to pinpoint to a certain Unmade that we have seen so far. I think during my second re-read of WOR it seemed likely to me that the other glowing inhuman form was Moelach.
"There is one you will watch. Though all of them have some relevance to precognition, Moelach is one of the most powerful in this regard. His touch seeps into a soul as it breaks apart from the body, creating manifestations powered by the spark of death itself."
We know that Moelach is the most powerful in precognition, so he would definitely have reasons to be on his way to Narak. I just have this feeling like Moelach might be the one leading the Unmade in a sense, and I do remember reading about him being "on the move" aswell from the Taravangian Pov not 100% sure however that might've been Nergaoul.