I really like watching this video, it's just insane ^^
Gratz, I actually thought about doing this a couple of times. You know when you wait for the first add to come, the boss is already at 90% health with nobody dps hard to save mana and cds, well with that in mind it's "easy" to down it.
Need an insane dps though, espacially Sarth10 ! 6k2dps for the warrior is really wicked. I think they could pack a mage though, I manage to get to 7k+ with all cds and bloodlust, which is like half of the fight