If you read closely at the top left of the image, it says SYSTEMA, and to the right, Tristram. I haven't really stayed up to date with the hype, but what if, during the events of Diablo 2, the dark wanderer(Diablo) was traveling around the globe to places of power so he could open a direct portal to some place other than hell, see the left picture in Cain's diary.
The center of the system being the World stone, or the location of this picture.
e = limn->infinity (1 + 1/n)n
Might be the sum of ?
Perhaps the corruption of the world stone was only final piece of a plan to open a gateway to where evil hides, not just where Diablo hides. Not a portal to the chaos sanctuary/river of flame, but a portal to hell so earth can be used as a staging ground for an assault on heaven? :/ Seems interesting...
First post. :P