I've been camping this guy on/off for a few weeks, killing every PH in the tri-state area :) and no spawns, even during the recent bonus spawns from the extra life event. Finally, tonight, after I killed a few of the slavers, he BAM just appears.at /loc 63.21, 151.38, 2.90. This was out in the tunnel, not in the room where the Overseer guy is, although I had been killing all 4 of the slavers in there too. Was beginning to think this spawn was broken! lol - or on an extended vacation. Hope this helps! :) He was the last one I needed for that expansion.
I fought this guy at least 8x so far. He have a PH if you are curious to find out where hespawn at. His PH is that Slaver troll that roam back and forth in the 4 room where the captains spawn. Kill that PH and eventually the Brawler will spawn. ONCE he Spawn he he is a roamer, but he always remain in that room where the captains spawn.
HE drop MOSTLY the signet of Vision as most of have found out as a "COMMON" drop or Uncommon drop. BUT he does have a rare drop not listed above. He drop this Etched Zraxthril Helm (Dark purple helm) once for me--Nifty LOOT!
Etched Zraxthril Helm AC 20 STR+2 DEX+5 Wis +4 Int +4 HP30 mana 20 Recommended lvl 43 Weight 3.3 Sized:Medium Class: War, Clr, Pal, SHD, BRD Race:All
This guy hits hard, but is PURE melee. One thing to note though: he breaks root OFTEN - VERY often. Soloing him as a 61 Druid was not impossible, but extremely burdensome. It's impossible to kite in the mines, so I recommend pulling him to the zoneline to Dulak. I was able to get all DoTs to stick without problems. He conned Dark Blue to me (as of the June 13th patch) and I estimate has between 12-20K hitpoints.
He popped for me in the mines area back near the room where Overlord Wrank spawns if that helps and dropped the Signet of Visions as I had hoped.