This guy also drops words of torment in addition to his other 2 drops. Strangely enough though every time he has dropped the words of torment he has also dropped the cloak. The words dont drop very often but in my experience (yours may vary) he drops these words approx 1 in 6-7 kills. The moss covered cloak is his common drop although he drops the bp fairly often as well. I would say the cloak drops 60-70 percent of the time with the bp dropping the rest.
He is at approx 268.88 -149.12 43.88 (well that is the safe spot for him) he or his ph will be straight ahead of you. His ph is a revenant and there is also a grandmaster to the far right of him. That loc may not help you but he is in the building with the grandmasters/initiates. If you know where the brother spawns then he spawns on the floor above him. After you go through the building with the sewers and rotting slavekeeper, go right and this buildings entrance will be acroos the hall. As soon as you go in this building go left and there will be a fallen pillar that you can walk up. Once you are on the second floor, run to the end of the hall and you will see the ph. As with most of Veksar the ph is different from the normal mobs ie a revenant being in a room with grandmaster and initiates.
After you get past the hands which require invis you can safely invis vs undead in this building even if the named are up. That is unless someone has charmed a mob which for some reason gives them the ability to see invis after the charm breaks.
Hope this helps you find him.
Noryn 65 warrior-Maelin retired~ Potus 65 necromancer of Aerist on Vallon Zek