I 4 man him on my shammies (not trying to brag, just stating that my tactic works 8| )
The clue is to NOT run up and place the EEs, they will die way to fast
In general i pull from max range, getting him to 85% just before he reaches my boys. (if you die at 14% then congrats, you got your last 14% right there)
When he spawns pure energy he stops, buying me another 2 seconds, so 1LB then i drop my EEs, then calmly press "4" two times DO NOT PRESS TO FAST (/stopcasting /tar pure energy /cast earthshock on round robin)
From there in its a DPS race, only stopping for a heal once or twice through the figth. At 25% stop to heal before the last push to get him down.

Using the "slow" tactic with a tank generally means i go OOM from healing before 25% and going full DPS usually means suicide.
I dont think i have time for HC MGT tonight, but if i get the time, ill fraps it