Less-Rabi question

[Brudish]

Think they first time I got it it was a Prot Warrior Boomkin, Ret Pally, Warlock and myself. (mage)

[autodidact31]

Completed this achievement a few days ago as the last achievement for my red proto drake, and I will explain the method we used.
Our group formation was myself (prot pally), a feral druid, an enhance shaman with reverb, a shadow priest, and a rogue.
As you (should) know, for every 1% of health the boss loses, he gains in 1% speed of his casts
e.g 75% health, +25% cast speed (turning the 4 second cast of transformation into 3 seconds)
From 100% to 50% we just had a steady burn, with minimal dots (will be explained later), no cooldowns, pots, or anything used during this period.
As soon as he hits 50%, stop ALL dps, because after 50% he will cast transformation every 5 seconds as opposed to every 10 seconds, which is where the reverb shaman comes in. So since the group has stopped at 50% (dots and white hits will bring it down to say 45%), the cast time of transformation is ~2 seconds, making it very easy to interrupt. Now, once the shaman has windsheered the first transformation, all the shaman has to do is spam windsheer, and the rest of the group can go nuts on DPS. The cooldown on windsheer is 5 seconds because of reverb, and the boss casts transformation every 5 seconds, so do the math, it's ties in like clockwork. It worked on our first try, we could not even see the cast bar of transformation, and it was interrupted, so that is your best bet, and it worked flawlessly. Good luck

[Xs]

Protadin
Holy Priest
Retadin
Ele Shammy
MS War

Having 7 interrupts to blow made it piss

[Bananengurke]

5 DK's, first do normal dps until 55%, then all 5 start casting army of dead
and you have one person assigned for the first interrupt, and two people for the second one, and for the last also two people ( depending on your dps )

now don't ask me how to do this as a warlock