Faerlina is the second boss youÃ¢â‚¬â„¢ll run into within the Arachnid quarter (Spider wing). She is flanked by 4 mobs. Do not kill them all at once. They need to be tanked in the side or just let loose running around.
Faerlina will go into a Frenzy after every minute has elapsed from the last dispel (or a minute after the fight begins). She will hit the tank extremely hard and he will not be able to survive for more than a few seconds. The only way to dispel Frenzy is to bring one of her mobs on top of her and kill it. Only then can the effect be dispelled.
Stay mobile and keep moving. Watch out for Rain of Fire.
So thereÃ¢â‚¬â„¢s a two stage encounter. The first stage is a simple tank and spank while keeping the mobs away from her. They are absolutely needed in order to remove frenzy. If you kill one by accident, then the time you have to kill her goes down. You can DPS them but donÃ¢â‚¬â„¢t over do it. I suggest using mild AoE to bring them down to approximately 20% or single targeting them.
In this case, notice how we established icons on all of the different mobs. We did it so we could coordinate the kill order (Ã¢â‚¬Å“Triangle first, move square out, ease off of XÃ¢â‚¬Â).
One healer on the main tank, one healer on the raid, the last one floats. The moment she goes into a frenzy, drop everything youÃ¢â‚¬â„¢re doing and get on the MT right away. Priests, use mitigation spells as quick as you can. Actually, IÃ¢â‚¬â„¢d advise your tank to use one of his panic buttons (trinket, talent, skill, whatever) right away until they get the hang of this fight.
After that, repeat what you just did. Wait until she frenzies, drag a mob over, kill it. Rinse, repeat.
However, you are on the clock. Once the last mob dies and she enrages there is no way for you to dispel it. When I did it, she went down between number 3 and number 4.