Sent hours camping several of the mobs listed about hoping to get Phased Seminal. Went to Eazack the Cruel camp. Boom! Got em! Hep popped for us at worst 2 PH then 1 named. Some times he popped back to back!
His location in Hatchery is 0, 85, Neg 30. Or....
Zone in to Hatchery. Go straight, not left or right. PH is at the bottom of the ramp just before going into the room. You can single pull him all day and night NO problem! Towards end of fight he does flee a bit and you can not stop that! A Construck and or Sokalar come by once in a while to make things interesting.
Again, if you want Phased Seminal go to Eazack camp unless you love spending oodles of time for nothing!