The raid entrance to Ny'alotha works in a different way from the usual raid entrances - The raid entrance changes, depending on which zone is currently being attacked by N'Zoth and his minions.
As an assault is always going to be up at all times during Visions of N'Zoth, so will be a raid entrance to Ny'alotha.
The entrance should change once every week, on the Tuesday reset, and you are able to see which zone currently has the Ny'alotha entrance by searching for the obelisk icon on your map.
Ny'alotha will be composed of 12 bosses. It is currently unknown if bosses will be linear or you are able to choose your progression path.
Wrathion, the Black Emperor
The Prophet Skitra
Dark Inquisitor Xanesh
Shad'har the Insatiable
Ra-den the Despoiled
Il'gynoth, Corruption Reborn
Carapace of N'Zoth
N'Zoth, the Corruptor
The Raid Finder difficulty, set to release slowly over a couple weeks after the release of Ny'alotha, has 4 wings for the raid, with presumably three bosses each:
Vision of Destiny
Halls of Devotion
Gift of Flesh
The Waking Dream
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