The Bastion of the Triune, or simply the Triune, is an uberlevel accessible through the Profane Cells in Caldeum, and contains the entrance to the Rathma Square, which is located immediately next to the southwestern entrance to the Triune. On Destruction difficulty, it is notably the only source of Cycles in the game.
The White Temple of the Cult of the Triune. The symbol of the trinity is pervasive throughout their rank and architecture. Uldyssian broke the Templars' armies on the battlefield in his campaign to obliterate the Triune and the Cathedral of Light. Lilith, the Mother of Sanctuary, finally corrupted Uldyssian, and thereafter the Dark Edyrem sealed themselves away. Lilith reestablished the Triune and installed Arihan as the sole High Priest. However, and fortunately for the forces of light, it is said that an aspect of Primus haunts the great temple halls of the Triune, seeking revenge for his usurpation by Arihan.
Points of interest
The Triune is home to three bosses: Arihan, High Priest of the Triune, Primus' Messenger and Vaca Loca, King of Meat. Arihan is the main boss, and can only be killed by Primus' Messenger. In order to make them fight, players will need to acquire the Tome of Possession from Vaca Loca, which unlocks the Dire Charm skill, and use it to charm Arihan.