When Rallos Zek was slain, his essence destabilized the Ethermere. Somehow, this enabled a Cazic-Thule from an alternate reality to begin forcing its way onto this plane of existence. This alternate Cazic's efforts have caused the essence of the Plane of Fear to bleed over into the Ethermere, and the result is the Fearcreep. Evil eyes and shiverback gorillas native to the Plane of Fear can be found roaming the area, and many of the native creatures have been corrupted by the essences of Fear.
Several Amygdalans in the service of the real Cazic-Thule have entered the area and are recruiting adventurers to help fight against this alternate Cazic. They've established a small camp at ( -1356, 218, 614 ) /waypoint -1356, 218, 614 that is essentially the only safe spot in the entirety of the Fearcreep.