"Team Agnor" (6 toons including Sssith, thank you Sssith) was successful at working around the bug that prevents proper completion of the PoNightmare event for the Pally 1.5.
As usual, the paladin needing the event is group leader and raid leader. A raid must be formed even with only 6 people. Leaving one member out of Group 1 as a Group Leader (preferably a druid) for Group 2, say "I am ready" and it ports all but the Paladin into the instance and spawns the boss mob. During this time, that core group heads towards the stage and intercepts the spawns and kills them before they reach the stage.
The Paladin then joins the group with the 6th character in Group 2 and the group 2 leader says "I am ready" porting the paladin into the instance, not necessarily in the same section of the city as group 1. This failed for us as I could see Group 1 characters and target them but they could not see me. Even though to me, I appeared to be in the same section of the city with Group 1, I was actually showing up on the map still at Etumer with the Group 2 leader. Fortunately, the 6 person, #2 Group Leader was a Druid and succored to zone line, wiping us from the instance as Group 2 and clearing us to form another group and try again. Group 3 was formed with the druid as Group Leader and we worked our way back to Etumer and then the #3 Group Leader said "I am ready" and the Paladin was teleported to a different section of the city and levitated to the section of the city with group 1. In this example, the Paladin must have lev and climb onto the cone shaped buildings and lev to the wall to enter the city section with Group 1. Still being Raid Leader, the Paladin enters group 1 and meets the group for the remainder of the adds and the boss kill. I was visible at that time to Group 1 and able to target and tank the boss.
It worked for us and 6 people were able to bring down the level 80 Shade that spawns (undead) and loot the shard plus handle any adds that made it to the stage. We would be willing to assist Zedrique on this if he can play daytimes on Mon, Wed, or Fri. Thanks to Trackez for this strategy.