Hey there! :wave:
Before we start i'd like to claim that this is NOT
made by me under any circumstances.
The exploit or trick, is to be able to 4man, Flame Leviathan 10man Hardmode & 25 Man Normal.
YouTube - How to 4man Flame Leviathan - 10m hard mode / 25m normal mode in Ulduar!
If you like this, i'd highly suggest you to check his site out:
Tarou's WoW Guides - Completely free and up-to-date World of Warcraft guides.
Cheers.
~Gotowneds.