All monsters in Toraja as well as the boss Lilith start off invulnerable until dispelled by the very same Edyrems needed to gain access to the area. The Edyrem Key, a very rare random drop from monsters in Toraja, can be used on Hell difficulty to open a portal to Toraja from anywhere in Act 3; it only has one charge which cannot be replenished, due to the exorbitant cost of repairing it.
Now nothing more than overgrown ruins, Toraja once stood proud as a medium-sized city in ancient times, and has become legendary as the city where the nephalem Uldyssian recruited most of his edyrem to spearhead the uprising against the infernal Cult of the Triune. This battle is where the time portal leads you. Aid the edyrem in their battle against Lilith and the Triune’s minions.