Wow, this thing is a massive tower of everfrost. I've only ever seen little handfuls of the stuff, nothing close to what we're seeing here.
The intel we've collected so far suggests that fiends utilize large deposits of the stuff to trap the souls of the lost within it, like some kind of icy prison.
It would seem that Maulos, that horrible arch-fiend you just took down, had a different use in mind and was actually destroying this everfrost to unleash swarms of angry, frozen souls into the Clockworks. Had he finished the job, well, I don't even want to think about how many sweaters we would all be needing right now...