A year ago, I was 3-manning ICC. After multiple tries, we killed her. How?
Phase 3. Palatank dies. Mage gets aggro. Mage dies. So I switch pets and try to finish her off. But she had like 5% hp remaining.
She casts frost tomb. Again. And again. So I killed her. But I never understood why she hadn't frost-tombed me.
So, when I started testing her last week, I decided to find out what makes you a tank.
So, my tries told me that:
-FD didn't save me from frost tombs.
-if I grabbed aggro before she took off (by dismissing my pet), she would frost-tomb me.
-but sometimes she wouldn't
I quickly figured out that she didn't frost-tomb me if she melee'd me beforehand.
Besides, she didn't frost-tomb me the time I was merely at 5% aggro, having FD 5 seconds before.
I luckily got a try where she didn't frost-tomb me in phase 3 for a while. So I made a video and analysed it.
So, basically: I switch pets, using deterrence, and 30 seconds after the FD I get the frost tomb.
That is how I understood that it wasn't aggro + melee that protected me, just melee.
So, if she melees you, you are a tank for 30 seconds.
The strategy is:
In phase 1, try to grab aggro after her blistering cold, take a hit (it doesn't matter if it misses/doge/parry), and FD (if you managed to pull aggro without dismissing your pet. If not, wait for your pet to have more than 7K hp).
In air phase, intervention can protect you from a frost bomb.
In phase 2, switch pets while taking a melee hit. Then switch pets every time FD is off cooldown. An intervene beforehand will reduce damage.