What the achievement asks
Kill the last two bosses of The Eternal Palace: Za'qul, Harbinger of Ny'alotha and Queen Azshara. Ten points, account-wide, both factions.
They are the seventh and eighth encounters, so the six before them have to be down first. In practice this achievement means clearing the raid.
The two
Za'qul is the bridge between this raid and the next: he serves N'Zoth, and the nightmare he brings is the first proper look at Ny'alotha.
Queen Azshara ends the raid and the storyline that has been running since Legion. Ten thousand years of scheming, closed out here.
How the palace divides up
All three Eternal Palace achievements are needed for the raid to count towards the meta:
- The Grand Reception: Sivara, Blackwater Behemoth, Radiance of Azshara
- Depths of the Devoted: Lady Ashvane, Orgozoa, The Queen's Court
- The Circle of Stars: Za'qul, Queen Azshara
Since Azshara is gated behind everything else anyway, one clear from the entrance closes all three at once.
The parent achievement asks only for any difficulty. Raid Finder is enough for the whole of The Eternal Palace, which is not true of the other Battle for Azeroth raids.