anyways my build is
So basically once you are at his final phase which should be the only troubling part, you should always to be vaulting when you can in order to get the speed buff and I found that constantly moving around from end to end made it easier to dodge his attacks. If you ever get hit by one, which you most likely will, make sure to use shadow power/preperation/potion because 2 hits usually killed me. The hardest part is when he does the massive aoe and i found it easier to not even bother attacking him and just focus on dodging. Make sure to keep 60% speed up from passive or you will most likely die. Even so, it does seem a bit chance whether or not you die here but you will have to survive it 3 times. Its pretty fun fight and I would recommend trying to solo it a few times rather then group of 4 as it reminds of some of the hardest fights in dark souls.