New Strategy Guide for talents/rotations for Patch 6.2:
I won't be going into as much detail here, but simply outlining what spec's to use and what rotations from Millz to use on all Hellfire Citidel fights I have completed on heroic difficulty and currently 6/13 mythic with several top 50 parses on most fight. I will not be going into that much detail here, if you are semi-intelligent and willing to do the work, it's pretty obvious when you should be toggling through different rotations.
Ideally you want to be using Mind Bender if you have 2 or 4 pieces of T18 if you don't have tier 18 then run insanity , also set Shadow word pain target to 20 across the board
Hellfire Assault: , Set VT count to 2 across the board , manually cast cascade preferably went iron dragoon come out. AS, Twisted Fate , Cascade (If using insanity set high aoe unit count to 5 targets)
Iron Reaver : Cop Lite , VT count to 1 , Save cascade for flying phase , Cop Twisted Fate and Cascade
Kormrok: Cop Lite , Vt count to 1 , Save cascade for Hands , Cop Twisted Fate and Cascade (If using insanity set high aoe unit count to 3 targets)
Hellfire High Coucil : , Vt count to 3 , Use cascade on cooldown if blade master is about to use mirror image then save cascade for that , AS Twisted Fate and Cascade
Kilrogg deadeye : Cop Lite , Vt count to 2 , Use Cascade went the add spawn (If you are going down for the vision then save cascade for that ) , Cop Twisted Fate and Cascade
Gorefiend : Cop Lite , Vt count to 2 , Use cascade went the add spawn (If you about to get suck into the belly then save cascade for that ) , Cop Twisted fate and cascade ( AS if you are progressing on mythic)
Shadow Lord Iskar : , Vt count to 3 , Save cascade for the add phases , AS Twisted Fate and cascade
Fel lord Zakuun : Cop Lite , Use Halo for this fight and try to be at boss max range to get most damage from halo , Cop Twisted Fate and Halo
Xhul'Horac : , Vt count to 2 , Save Cascade for Imps , AS Twisted Fate and Cascade
Socrethar : , Vt count to 2 , Try to use cascade on haunting ghost if you can't then just use it on cooldown , AS Twisted Fate and Cascade
Tyrant : , Vt count to 2 , Save cascade for add , AS Twisted Fate and Cascade ( Glyph of Reflective shield and pre shield yourself during Edith )
Mannoroth : , Vt count to 3 , Save cascade for imps and infernals , AS Twisted Fate and Cascade ( Glyph of restore faith is really nice to repositioning yourself after shadowforce )
Archimonde : , Vt count to 2 , Save Cascade for Adds , AS Twisted Fate and Cascade ( Glyph of Reflective shield and try to pre shield yourself for some extra damage)