Worldkiller Iris - Discover Zovaal's Symbol of Despair with Unique Sepulcher Raid Loot

wowhead.com:

Loot was finally added to the dungeon journal in this week's Patch 9.2 PTR build, giving us a first look at some of the items which will drop from the Sepulcher of the First Ones raid. The Jailer Zovaal drops several interesting pieces of loot at the conclusion of his encounter, but the Worldkiller Iris is interesting not because of its effect, so much as its resemblance to another familiar artifact and the lore implications they share.

Although dramatically under budget, the Worldkiller Iris has a familiar icon and secondary stats as another well known artifact. The unique neckpiece in the Jailer's loot table lacks an exciting unique effect, but those who played through Battle for Azeroth will likely recognize the icon as belonging to the Heart of Azeroth, not to mention the unique stat distribution.

Despite similarities though, the names are very much at odds with one another. The Heart of Azeroth was a key instrument in saving the planet, but although it wasn't a «world killer,» it contained no less destructive power, being used to channel power from the Engine of Nalak'sha and Forge of Origination to obliterate N'Zoth at the conclusion of Ny'alotha.

Although the Jailer boss encounter is not being tested on the PTR and will not be available until the second week of raiding in Patch 9.2, from what little we've learned through the dungeon journal, the battle with Zovaal will take on a cosmic scale and threaten Azeroth directly. We've known for some time that the worldsoul is key to his plans, probably in a similar fashion to how it has been speculated that Argus' soul broke the previous Arbiter.