The aura that appears around some mobs, sometimes when using acidic blast is blocky. I last noticed in the cave like lvl of shadows embrace.

Also, I notice that when multiple Geist like mobs are attacking me, I experience a significant lag due to the black cloud effect around my toon. Zooming out helps somewhat.

there was another post about this in the boards i've had the same problem. with the poison cloud and the lag from the geists black cloud thingy.. another person has had the same blocky problem and has for quite the while. stephen had resonded a while ago to the other post. so i know the devs are aware of it.