To fellow DH's dont give up , i had around 60-70 wipes there (maybe 20 or so cuz i just tryed to rush things and and killed myself) , worst of all i got a wipe when the boss had 900k HP left i got so hyped that i will kill and forgot to make 2 steps back to get out of the darkness.... ye that happend.
On the kill tho if you have the chest and the neck like i did but no other dps legendaryes dont worry u;re cover i didnt used netherwalk as a talent but i completed this with Soul Rending , at the end of the day you can down the boss if u get enough practice and dont try to rush things up ... my best attempt was with First Blood and i had plenty room left when i fked up at 900k hp , but the kill i got it with Bloodlet but i was out of room and i had to pray that the leech from blur(with leg chest) will keep me alive and it did ( healing pot aswell ) boss died and i was left with 15k hp .
By now i think most of you saw Vivie video or whatever his name is , my point is u dont need bloodlet bracers or the prydaz or healing chest(sure they help ALOT) , if u dont have healing chest u can use soul rending like np just try to be as close as possible to the middle of the room before he teleports.
Play safe p1 its about safe and positioning before teleport P2 its as good as its gets on your dps
Oh and BTW after 30 or so started to be very unbearable hearing to 'my magnificent self' i gave up on sound and played music only god that mage is mmmmmmmmmmmm hate him good thing im done never again