So today I was killing this boss for battle pet drop. He is working fine until last moment... Whole mechanic behind freezing him is working fine but when he should crack and burst he came back into that 1 HP state before he start freezing all-out-again.
I've tested that with friend and when we were faster in melee he changed faster from that frozen state back into normal. According to wowhead there is 30 seconds to kill him in that state but he became normal after like 5-10seconds (we had 2 champs, 2 pets + hero)
Even if he starts moving again after getting frozen, if u have enough melee hits, he will shatter. Btw u need to melee 75 times in 15 s not 30 in 30s i think. Also what class are u playing as only melee hits count not ranged.