Sepulcher of the first ones

The Sepulcher of the First Ones is a First Ones-style structure overlooking Zereth Mortis from a secluded island on the eastern end of the zone. Initially, you will need to use an Ancient Translocator located east of Pilgrim's Grace to get to the raid which is unlocked at the end of Chapter 4 of the Patch 9.2 questline, Forging a New Path.

The raid entrance is located on a floating isle in Zereth Mortis. First, you must fly to Pilgrim's Grace.  Upon arriving there, climb up a set of stairs to your left, interact with the Ancient Translocator to fly to the Sepulcher raid.

After flying is unlocked in Zereth Mortis, you can simply fly to the raid entrance. 

Ilevel requirements follow similar trends to previous raids of the expansion, where the majority of the bosses have a specific set ilevel for loot they drop, with the final three being higher (and thus, will no doubt require a higher ilevel to defeat).

Sepulcher of the First Ones Boss Order

Sepulcher has a semi-linear boss order, with a few points where you need to defeat all available bosses before being allowed to continue. 

Tier Set Armor Pieces

Tier Set armor pieces drop as tokens from bosses in the new raid in Eternity's End. Below, you will find a list of bosses that drop specific tier set tokens.

The Raid

The Jailer has breached the Sepulcher, the mysterious heart of the Shadowlands. Should he control its primordial power, he will reshape the cosmos with Death at the fore. As Zovaal prepares to dominate reality, champions of Azeroth charge forth to stop him. Will their resolve outmatch his?