I thought I had the routine as a 57 druid. KEI, soe, chloro, damage shields, virtue were all fine enough buffs. Mana pool was over 4000. Dotted, ran, dotted, ran back and forth while he chased me. I even got to sit a bit and med (like for 6 seconds at a time while he ran back into my spell range!).
But then the third time he generated a LIVING SHIELD - a bulthar who ran with him. The couple of times I brushed them as I ran past they stunned me. So after the herdleader died, I had to deal with his living shield (snare root dot dot dot dot, etc.) At the end of it all, I had about 20 mana left.
By the way, he and his herd can be found at the bottom of the cliffs just northeast of the entry to Skyshrine.
BV
Edited, Mon Mar 13 00:11:27 2006