UPDATE: There is a new bug in the High Celebrant mission. Now, the High Celebrant has an Immune issue that tricks players into thinking he is not damageable when really, he has to be damaged enough to trigger the next phase of the mission.
High Celebrant Immune Bug (NEW BUG)
The High Celebrant will go immune while still damageable. This is the latest bug in the Coup De Grace Mission. Previously, the High Celebrant wouldn’t teleport out of the starting room, now he appears to be immune even when he is supposed to be damaged to trigger the next phases.
In the first phase, a shield may form around the High Celebrant, but most importantly he goes “Immune”. Keep damage on him until he moves under the archway. You won’t see damage numbers but you have to stand in the buff and damage him enough to trigger the next phase. Damage output is no longer an issue in this first phase. The latest bug is that the High Celebrant goes immune while he is still in his damage round.
The next time you see the High Celebrant he is in the room after you drop down the elevator. He will be immune during this entire encounter but he is damageable and has to take a certain amount of damage to progress the mission.
Ghost says “This isn’t working” and the waves of enemies spawn as Crow speaks to you. Kill the big guy with the buff, stand in it, and do damage to the High Celebrant. You will not see numbers but continue hitting him until he teleports to the back of the room and disappears (spawning the Ascendant portal).
In the final phase of the mission, you have to kill the High Celebrant. Again, he shows immune even though he is damageable. You will not see damage numbers. Kill the buff enemy and shoot the High Celebrant. Deal damage to him until the Barrier champ spawns, kill the barrier to trigger the end sequence. You will see his health bar dropping, even though you see immune text.
As the High Celebrant tries to leave Crow blocks the exit portal, you will be stuck in a green cage in the center of the room. Once it’s time for damage, your cage is released and Crow signals you to kill the High Celebrant. Finish off his health bar. It will still probably be immune, but he will take damage until he finally dies.
Bugs when first released, still may be an issue for some players.
The latest questline Coup De Grace for Crow in Destiny 2 is bugged. The High Celebrant is proving to be quite tricky to chase down in the Ascendant Plane. Currently doing too much damage to the High Celebrant in the Coup De Grace weekly mission will bug this mission and prevent you from activating the Ascendant Plane, forcing a restart of the mission.
Here is exactly how we worked around the High Celebrant bugs in the Coup De Grace mission. First off, and most importantly do not do too much damage burst damage in the first phase of this mission.
Step 1. Place the lure inside the mission to spawn the High Celebrant.
Step 2. Let him spawn start doing small amounts of damage, he is going to port to the center of the room. Use primary ammo until the Knights spawn.
Step 3. Kill the Knights then stand in the green glow and continue to tick down his health. Do not use high damage like Anarchy or Xenophage as you might do too much burst damage and bug him out.
Step 4. Continue slowly ticking down damage until you reach about 50% health within the first chunk of his health bar. The High Celebrant will have three chunks of damage, you are looking to get the first third down to about 50% health.
Step 5. Once that first chunk of health has about 40-50% damage dealt refrain from high damage and stick with Primary Ammo. Continue to pepper him down until he teleports under the arch.
Step 6. Stop damaging him once he is under the Arch.
Step 7. Crow will begin speaking once he disappears, leave him and the Blight Orb alone. Do not shoot anything.
Step 8. Let Crow speak his full voice line, once he is done, wait 10 seconds and then shoot the Blight Orb. So long as you didn’t burst him down too quickly this will spawn the Ascendant Plane.
REDDIT recommends doing this solo, we have also had success with this solo, however, we have determined based on our own trial and error that the bug is activated by doing too much burst damage to the High Celebrant.
Second Section Bug: Engage the High Celebrant
After going through the Ascendant plane you will encounter the High Celebrant a second time. You will be engaging him on a circular platform. Take the remaining first third of health, leaving him with his remaining 2/3rds health. Allow him to stand for a brief moment before the mission is complete.
The step should now saw Destroy The Residual Energy. Shoot the Blight orb after you see this mission segment change.
Third Potential Bug
On the final step of “Execute the High Celebrant,” you will want to get his health down to about 15% of his last third chunk of health. A Barrier Servitor will spawn, take this barrier out first before killing the boss to prevent any more bugs from occurring.