Earth, Wind & Fire (25 player)

Ret pallys noob

Step 1: Recruit tanks that can pull 100k dps each, and heal themselves.
Step 2: Profit.

NOTE: THIS IS POSSIBLE TO SOLO

Given the large amount of comments that are leftover from WotLK, which suggest strategies based on a full raid, I figured I would explain how this is possible to solo for anyone looking to complete this achievement.

To get this, you have to kill Emalon and Koralon (the two bosses at the entrance to the raid) within 60 seconds of the final boss, Archavon.

Now, unless you are an extremely fast druid, you wouldn't be able to kill each of these bosses in their respective areas.

Kite Emalon and Koralon from each of their chambers. I suggest using a taunt, or if need be one can run through them, as any attack at max level will 1 shot the bosses. Kite Emalon and Koralon up to the hallway before Archavon, but DO NOT BRING EMALON AND KORALON INTO ARCHAVON'S CHAMBER. This will cause both Emalon and Koralon to reset to their usual areas. Kill Emalon and Koralon in the hallway before Archavon, then move into Archavons chamber and collect the achievement with plenty of spare time.

TL;DR:

Kite Emalon and Koralon to the hallway before Archavon, kill them both, then kill Archavon.