Essence of the Immortals

Essence of the Immortals was for some time on the PTR for patch 2.4 a drop from 25-person raid bosses in the Sunwell Plateau. Also, end-game bosses such as Lady Vashj, Prince Kael'thas, Archimonde and Illidan were dropping one essence per kill. Blizzard replaced the Immortals-system by having the three gates open automatically over time at equal intervals on all servers.

As a quest objective

 * Agamath, the First Gate (quest)
 * Rohendor, the Second Gate (quest)
 * Archonisus, the Final Gate (quest)