I am a huge fan of the fallen in destiny and was excited to know the witness set (formally kellslayer) was making a come back as well as the lord of wolves and the other HoW exotics. Naturally I have been playing Challenge of Elders a lot to get an Exotic weapon, but I am well over 40 runs of said activity and have had no exotic weapon drops in the post game reward screen. As much as I am aware Exotics are rare I feel pretty disappointed to have got none at all despite my time and efforts to the point in fact I feel I am missing out on content.