I did this fight on my MNK to help out someone we had x2 pld x2 whm x2 mnk and I guess the other 2 ppl were blm or brd idk. all you have to do is stun every voice move he does have one pld tank it and the other focus on stuns with shield bash I guess they get? I stood next to his back right leg just out of range of the breath attack and the back attack. when he does the ball of lightning and it targets the pld or yourself run. other than that if you are a caster make sure you don't get hit from the ice attack thing I forgot what its called. It took a few tries but we figured out that having only the pld stun was better than everyone so there was no DR on stun near his death cause it seems like he resist it over time and when he is below 10% and miss that stun your screwed. the only times I ever got hit was when stun missed. Sucks I will have to do it again but was easy.