So we were doing amber shaper tonight and during phase 2 one of our raiders that got reshaped said he hit amber strike like 5 times during the cast and it would not let him use it during the explosion. I thought it might of been a not in range issue or maybe he hit it too early....but then I got reshaped a couple attempts later and the same thing happened to me...the construct was auto attacking but when it came time to interupt i hit it nothing...hit it again and nothing. Is there a reason that this would happen? It might be the tank got flinged and he ran just out of range but still seemed odd for it to happen twice. I am also positive it wasnt on cooldown.
what they said; since you only have like 4 buttons (and should know what they do from LFR), and only need to be in melee range of it, you should be able to watch the DBM timer telling you when *you* are going to explode, and when the *boss* is going to explode, and from there figure out the best course of action.
Though it's been a while since I've done that fight (hooray for extending HoF lockout to get heroic Shek'zeer kill, and now spending the rest of our time in heroic ToES); if memory serves, he should transform someone as soon as phase 2 starts, and again just before the monstrosity does it's explosion -- otherwise the first guy will either need to drink a pool to extend his time, or the 2nd guy will need to be quick about getting to the boss and interrupting it.
If you're doing it right, you shouldn't spend more than a a couple minutes in phase 2, and have enough stacks rebuilt on the boss to make the last phase go by pretty quickly too. On heroic, the only real trouble is getting people with the amber-glob-of-certain-death to do it right (if you've ever done Sinestra when it was relevant in Cata, it's a pretty similar mechanic to the death laser).
The Sun was born, so it shall die. As we were forged we shall return. I know in darkness I will find you, giving up inside like me.