I actually do Haste > Versatility. Most of my gear I tried to get Haste and Versatility but where I could not I’d do Haste + Crit or Versatility + Crit. Mastery is to be avoided if possible but iLVL and Agility take precedence over specific secondary stats. Haste is crucial to get Fracture, Immolation, Glaive and Demon Spikes cooldown reduced.
If you’re having trouble living you may need to get some better gear. Also, make sure you use flasks(agility) and food buff(haste or agility) for anything M10+. When I was doing my Mythic 15s I shelled out money on the AH to make some of those big buffet tables to get the big primary stat buff for the group. Always appreciated by the group. EDIT: Also Oils.
Now here’s what I typically do. I’m Kyrian so if you’re not you may need to adjust.
If the pack is already close together, start with Elysian Decree and immediately leap into the group, hitting demon spikes and immolation aura as I land. I then follow it up with Fiery Brand on the most dangerous target to get that to start spreading through the enemy group every 2 seconds. Fracture, Cleave, alternating if possible, about 2 times each. Then Demon Spikes again. Fracture, Cleave. If fracture is on CD and cleave doesn’t have enough fury to use then glaive is good for maintaining threat as well and hits multiple targets. Towards the end of the pull I’ll sometimes save up fury for the next pull.
The second pull I won’t have elysian decree so I jump in, immolate+demon spikes and backpedal, to get everything in front of me and hit Fel Devastation to aoe and establish threat. Glaive also helps. Then fall into the fracture/cleave rotation, occasionally hitting demon spikes. If the fight gets a little hairy hit Metamorphosis if possible once Demon Form from Fel D wears off.
My thought process is this. To maintain the speed and make time I alternate the two small cooldowns of Fiery Brand+Elysian Decree and Fel Devastation. I had to train myself to resist popping CDs towards the end of fights or even in the middle sometimes I would hit Elysian Decree and regret it because at that point it’s pretty unnecessary. You’re not there to rank on DPS meters, you’re there to maintain threat and take damage/kite. I’ve had friends be like “yeah but if I kill stuff faster then that’s less I have to be healed.” Which could be viewed as mitigation but I don’t want my healers to get bored.
I used to take Quickened Sigils for faster pops and lower CDs but Sigil of Chains is extremely useful when you have to kite. If DPS is taking too long, drop chains, leap out. Throw glaives from a distance to try to keep aggro. My Talents are 2,3,2,3,3,2,1. Sigil of Flame is almost never used. I use silence to cancel spellcasters and pull them in a bit sometimes and I use Fear to interrupt uninterruptable spells/abilities when I can. Chains works for that too.
Edit: Note Demon Spikes does not invoke GCD or break channeling so it can be popped at any time, even while you’re doing something else like FD.