Durendil: Ah, another impossible boss… how to survive infests after a necrotic plague? All it took was a hunter mad enough to try him on 10 heroic at level 85, and somehow end up running around with his pet dead and FD on cooldown while a mean-looking boss was trying to catch up.
I did it in 380 ilvl gear.
The main difference with the solo at level 85 is survival. Seriously. Crab tanking the boss and 4 spirits? Standing in the remorseless winter? Taking 5 melee hits and a soul reaper yet being full for next infest? It was all about strategy (surviving the insta-kill mechanics while dpsing enough).
Phase 1: Use a spirit beast. You’ll want to put the second plague on the adds, and heal yourself after necrotic plague ticks. To avoid infests, just go behind a pillar. There are two ways of keeping adds on pet: use glaive shot (I’m supposing all your shots have misdirection macro’d into them) or stand near the boss and multi-shot, your beast’s cleave will take care of the rest.
Phase 1.5: kill spirits, and continue to heal yourself with your spirit beast. You’ll want to focus on spirits before the boss. Remember to taunt the last spirit to get hit (for those who didn’t watch 10-man video: melee hit = 1 minute of tanking, so Val’kyr won’t pick you up).
Phase 2: nuke boss, this is just a patchwerk-style phase. Except you’ll want to taunt every other infest so if things go wrong you’re back to full for the next one.
Phase 2.5 and 3: Final rush. Use all cds to survive, and misdirect spirits on the pet. When remorseless winter ends, you might want to take a turtle, but in this case FD on spirits. I kept my crab for the mastery buff.
Next phase: solo him on heroic. Better hurry up, death knights, I’ll have a go at him as soon as it becomes theoretically possible!