The Crown of the Immaculate Trial

The Dancing Plague   The Crown of the Immaculate   The Dying Gasp   The Dancing Plague (Extreme)   The Crown of the Immaculate (Extreme)   The Minstrel’s Ballad: Hades’s Elegy
The Crown of the Immaculate was added in patch 5.0 of the Shadowbringers expansion.

The Crown of the Immaculate becomes available at level 79 as part of the “Extinguishing the Last Light” quest, which is given by Chai-Nuzz – Kholusia (X:18, Y:17).