i personally wasted a lot of time trying to beat it as unholy with actually beating the lightning phase instead of skipping it, like hunters. but it seems like i choose the wrong tactic this time since i couldnt handle the it as unholy.
anyway it took me 4 trys to down this boss after using this tactic with my new 517 weapon.
song: Kid2Will- Club Sprud
http://www.youtube.com/watch?v=S7CKc5Wikfc