Originally Posted by
Rustynip
The way I did that fight was:
Spec: Arms
Glyphs: Sweeping Strikes, Unending Rage, Death from Above
Talents: T1- Double Time; T2-Second Wind; T3-Any; T4-Dragon Roar; T5-Vigilance; T6-Stormbolt
Make sure you keep a high up time on Sweeping Strikes only while in the leg circles so that you're not wasting rage when you don't have the damage bonus (or two targets for that matter). The reason that I take SB over the other tier 90 talents is because its damage is copied (less 50%) completely to the boss. Stormbolt hits pretty damn hard on that fight too because of the legs damage taken increase. Try to maximize this by lining it up with your CDs (Reck, Synapse Springs, CS debuff, Enrage, etc..). If you're feeling low on rage try to stance dance for when Crush goes out, then back once its over. That'll give you a nice little boost every now and again. Also, if there are no legs up that you can attack, get some boss DPS in but don't waste your SB if you know a leg will be coming up again soon. Come Execute phase, pop your last Reck and your CDs ON THE LEG! This will boost both your dps and the damage to the boss because for every leg you kill, the boss loses 3% of his total health. Faster leg deaths = faster boss death.
This isn't necessarily the best way to do this boss since I haven't tested Avatar or Bloodbath but this is the way that I got my first kill and it seemed to work out very nicely.