Unsure if anyone has found this one yet (Havent seen anything for it.) I just looted Spark of the Forsaken Exarch, a Skin for Truthbringer (Prot spec) After completing the withered army mission completely. (Had 45 withered, cleared the entire dungeon and got to the very end) Unsure if it was just RNG from the box, or if you need to complete something specific to get it but.. I got it boys! (and girls ) Will post a picture in a moment
http://i.imgur.com/oZSgYIY.png
^^^^^^
Picture of it, it matches the crystalforge set so well