What the achievement asks
Defeat the 11 bosses of Sepulcher of the First Ones, on any difficulty. Ten points, account-wide, both factions.
Sepulcher of the First Ones is the last raid of Shadowlands, in Zereth Mortis, and the longest at eleven bosses. It ends on the Jailer, and with him the expansion.
Any difficulty means Raid Finder
This is the sentence worth reading twice, because it is not how the Battle for Azeroth raids work. Three of those demand Normal or higher; none of the three Shadowlands raids does.
A full run through Raid Finder awards this achievement exactly like a Mythic clear. For anyone coming back to the expansion for the meta, that turns three raids from a scheduling problem into a queue.
The 11 bosses
| Order | Boss |
|---|---|
| 1 | Vigilant Guardian |
| 2 | Skolex, the Insatiable Ravener |
| 3 | Artificer Xy'mox |
| 4 | Dausegne, the Fallen Oracle |
| 5 | Prototype Pantheon |
| 6 | Lihuvim, Principal Architect |
| 7 | Halondrus the Reclaimer |
| 8 | Anduin Wrynn |
| 9 | Lords of Dread |
| 10 | Rygelon |
| 11 | The Jailer |
The three raids of the expansion
All three are needed for the meta, and all three accept any difficulty:
- Castle Nathria, 10 bosses
- Sanctum of Domination, 10 bosses
- Sepulcher of the First Ones, 11 bosses
Raid Finder splits each of them into wings, so none has to be done in one sitting. The wings unlock in order, and the last one holds the boss everybody remembers.