Our raid makeup was 3 healers, 3 casters, 1 hunter, 1 melee, and 2 tanks. Phase one and two were easy enough (once someone figured out how to get out of the frost nova), and we were regularly getting into P3 without issue. This is where the wheels would come off.
Unchained Magic AoE
This is the debuff casters get during the encounter. In regular, you can eat six or seven stacks without issue (and you can in Heroic during P1/P2), though in Heroic there's a new twist. When the timer goes off and your stacks reset, you don't just take damage, you do AoE damage based on the number of stacks you have.
This can pose a problem in P3 when the Buffet stacks are going out. If someone has six or seven stacks of the Buffet, they're probably fine (providing they don't get a debuff), until you run by and AoE their face off.
The other problem you'll have is that if you don't drop your Buffet stacks on every ice block, you run the risk of getting insta-gibbed if you happen to be the next beacon target. So not dropping your Buffet stacks is kind of like playing Russian Roulette.
First, with 3 healers and 3 casters - we could guarantee that every Unchained CD one healer and one caster would have the debuff. Every Frost Beacon one healer would be basically standing with their hands in their pocket (dropping their buffet stacks), one healer would be responsible for the tanks, and one would be avoiding anything because of the Unchained debuff.
Some things were just not working smooth.
- Blocks dropping too fast - tanks weren't able to drop their Buffet stacks, get one shot.
- Positioning - people chaining blocks because they were in the wrong spot.
- Healer who had to not drop stacks gets next Frost Beacon. HNNNGGGGGG (CDs can help here).
- Missing Unchained debuff and running up 6 stacks in 6 seconds.
Hopefully Blizzard fixes the Hellscream's Warsong buff on Bladefist this week. While we shouldn't need the buff, I won't say no to it.