Армори того лока
1) Clear to Vexallus Magister's Terracee 2) Create a macro similar to this: /target pure energy /petattack.
3) Make sure your felguard ONLY auto attacks to get maximum benefit (energy spawns are % based).
4) Start attacking boss and whittle him down to 80%. When the first energy(s) spawn, hit your macro until they are all dead. Then set your pet to auto attack the boss while spamming your macro.
5) This is the important part: the stacks disappear AFTER the boss dies, then DISMISS your felguard.