Pillars of Creation

To complete this achievement, you have to do all the campaign quests in all the zones.

To get the Eye of Aman'thul, you have to wait for the Nighthold questline in Phase 2 of Legion: Remix.
If you haven't already, complete the Suramar campaign: "Good Suramartan" and continue with the Insurrection storyline.

At the end of the storyline, you'll get a quest from Oculeth: "Breaching the Sanctum" to go to the Nighthold Entrance, where Kadgar gives you another quest to kill Gul'dan: "The Nighthold: Lord of the Shadow Council".
You turn in the quest to Kadgar inside Nighthold after you've killed Gul'dan, whereafter you have to do some RP-stuff with Kadgar where you "teleport" the artifact to Dalaran, in the quest: "The Nighthold: The Eye of Aman'Thul".

Remember to talk to Khadgar inside the raid - DO NOT HEARTSTONE OUT!

Create a nightborne in Legion Remix to earn this achievement. You will receive it and the bronze cache upon logging onto that Nightborne.

You will receive credit for "Eye of Aman'thul". If you already have the other criteria, then you will get credit for the achievement.