The Elder Scrolls Online, but those huge portals of darkness tearing open the sky and shooting anchors into the ground? Those are not good news. The Dark Anchors are visible manifestations of Molag Bal's power, an attempt to pull Tamriel into his realm of Coldharbour, and the latest development diary explains exactly how these pulling mechanisms were conceived and designed.
Originally, anchors were smaller in scope, but the team wasn't happy with the idea that these were local things. As a result, steps were taken to ensure that Dark Anchors were visible from far away and had wide-ranging effects, giving players a solid indication that something Very Bad was taking place. If you want to gaze deeper into designing the yawning maw of darkness, take a look at the full development blog for more details on how the anchors took shape.