Through a Glass, Darkly
Look into the Eye of Eternity at the Nether Vortex in the Nexus.Meet Tarecgosa inside the Nexus where she will escort you to the rift. A quest.
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I cannot enter the Nexus Dungeon to complete the quest, I still managed to go there at some point but nothing happens, there is no phase to complete the quest once there 'interior.