The Ensemble’s Refrain is the final challenge in the Vault of Glass in Destiny 2. This takes place during the Atheon fight and has players dealing with the Oracles in a very specific manner – this is why it's called the Atheon challenge. Completing this challenge will earn players extra rewards, provided it’s active on the raid. It can also be completed at any time for the Triumph.
Ensemble’s Refrain challenge/Atheon challenge – Vault of Glass
To complete the Ensemble’s Refrain challenge, players can only defeat one Oracle in each set of three. What this means is that the three players that get teleported will need to destroy one Oracle out of every set. If a player destroys two out of three oracles, the challenge will fail. This one can take a bit of practice to get squared away.
As always, before you attempt the Ensemble’s Refrain challenge, make sure everyone in your fireteam not only knows how to defeat Atheon, but is also intimately familiar with the Oracle positions and callouts.
Now, Atheon will always summon nine Oracles, but they appear in three sets of three. Each player that is teleported will be responsible for defeating one Oracle in each set. For example, the first three Oracles spawn and each player defeats an Oracle. Then, the second set of three Oracles spawn and the players each defeat an Oracle. Finally, the last set of Oracles spawn, and each player defeats one Oracle each.
Here’s the real rub of the challenge: because each player can only defeat one Oracle per set, it means the Relic holder must drop the Relic and defeat one as well. To make it easier, have the Relic holder always kill a specific Oracle, either the first or last one that spawns in a set.
By assigning the Relic holder to defeat the first Oracle, the other two players need only work out who is killing the second and third Oracle. Clear callouts are critical as incorrect Oracle spawn order readings and someone killing two Oracles will fail the challenge.
For this encounter, Xenophage will one-shot the Oracles, which makes the whole attempt run rather smoothly. Players that have a more advanced fireteam might do well enough using Primary and Special weapon fire. If you’re really struggling, it might be worth helping each other kill an Oracle, but be careful not to destroy two Oracles.
When the Ensemble’s Refrain challenge is completed, you’ll unlock the Triumph and some extra Vault of Glass rewards if it’s the active week in Destiny 2. The Atheon challenge will take a bit of practice, so don't give up! Be sure to check out the Shacknews Destiny 2 Guide for more Vault of Glass raid challenge walkthroughs.