Originally Posted by
Maxweii
I use Roiling for the majority of the fights mainly because I am lazy, there are times where Unholy Blight plays into the Festerblight 2.0 style play. It allows for easier application of max strength dots, but I wouldn't say it's "required" to do it, just helps your chances of getting super dots.
Say you have two target, A and B. You have stronger dots on B then compared to A. If you roiling from A to B, you destroy the stronger dots. However if you roiling from B to A you keep them, but A does not get the stronger dots as it's still based on your current AP not from the dots on the mob.
Cay, Plague Leech shouldn't be used as Unholy.