Someone please give me some good advice for this encounter. I've tried so many times, I've wasted hours of time waiting in queue to just fail on this boss.

I'm using the glyph of Dark Succor for the Death Strike healing, but it's just not enough.
I've tried so many times but I'm just starting to assume that I'm under geared.
Edited by Pain on 1/13/2013 8:43 PM PST