Yeah I got a feeling he doesn't like warlocks however I bought 3 chest engram not long ago first I got voidfang vestments with a good stat then lucky raspberry with good stats (shard) I then said a little word of encouragement and a pause, it appeared right in front of me. ( The HOPF). I don't have much luck but today was a good day. Maybe a GHorn next month or a few months later.