dropped this guy tonight 4/26/2010, I found him fairly tough, mostly because of his knockback. Make sure you fight him in a fairly cleared out area, his AE can really send you flying!
He can also spawn near the zone in. If you were otw towards his listed spawn location, he'd be in that big hall with the fountain that is empty. He is a pather with a pathing location that takes him to the hall opposite the location I posted. About 2-3 ladderwells away.
He's also got a fun knockback / grav flux effect.. single target..^_~, part of tail sweep attack. sends ya flying, make sure you fight with your back to the wall ;)
Just before you get to the lower southern most room there are stairs leading down to it. On the right side of the stairs as you are facing down, there are 2 static mobs. The mob that is standing with his back to the stairs has consistently been the PH for this named. I wandered down there when servers came up on 03/19/2009 and he was up (another grp killed him). They left and he popped again. I killed him then went into the big room killing the wanderers as they popped. He never showed up again. The loc for the PH is -1469.46, 439.08. *Edit* He does also roam in the area indicated by other posts. A pita to spawn but got 2 in a row.
a vault custodian is the PHer, he wanders around. spawns in the lower southern most room and roams around . if u camp the NW corner of the SW most BIG room, the pher will wander almost straight to you, without aggro range tho. hope this helps.
casts what appears to be and ae blind and nuke, 4300 dmg, also something that said, "you are knocked back by a tail sweep. You have taked 7740 points of damage" and it tossed me into the air
He dropped the faceguard for our group today. He spawned for us in Kaesora Library, on the Library side in the southwest quadrant of the zone (as opposed to the circular pit-like area). He spawned in the big open area that surrounds the rectangular library room. No idea what his placeholder was other than we killed any mob that roamed and then whatever else we could snag. Yellow to 84, he blinded us (screen went dark, but could still cast) occasionally. He's immune to stun/snare/root. Max hit against a 4K warrior was 2.8K, average hit was around 1,450.