Do the phogoth strike. With at least one friend, easier when it was nightfall. Go back to Patrol Spawn area, go straight up the hill into that building that leads down to the hive cave with the two knights outside. Widdle them down, then nova bomb them when they are grouped. Go back up the hill and wait for them to Respawn. Takes like 20 minutes lol. So thats why its better if you have a fire team to wait for you. I did this, easiest way but you need the Exotic Piece that grants an extra orb. I think its the Helm of Ackamara or something.