Killed all three PHs more times than I remember.
Although surrounded by imps, the southernmost PH in the upstairs was easy to kill by targetting with Zomm, then just sending in pet whilst I waited outside. Rarely got any adds.
Middle PH stays behind counter and doesn't assist the other mobs in room.
Northern PH on the path junction can be pulled south to grass verge but there is some weird pathing near there and sometimes the PH runs off and scoops up half the zone as adds. Gate!
Dalyn herself spawns pairs of regular zone adds 4 times, similar to Master Sage Lowenn. Dalyn doesn't do much damage herself so deal with the adds or you'll likely get overrun by the adds.
110 Solo Mage. Air Pet, EM XXI