Con-speed-atory (25 player)

Important if you are doing it these days - you have to kill at least one trash mob before killing the boss, otherwise the timer won't start and you won't get the achievement.

Maybe obvious but I failed on that last week.

EDIT: The description has now been changed from "within 20 minutes of entering" to "within 20 minutes of first kill" making this comment obsolete.

Very important - YOU ARE NOT ALLOWED TO DIE AND RELEASE YOUR CORPSE DURING THE 20 MINUTES!

We managed to kill freya and all her sub-bosses in 19 minutes, but everyone, that died during those fights did not get the achievement!

On every ticket we got the answer, that they will not give us our achievements -.-
Nice one blizz...

This achievement seems insane, to be frank.

Freya herself will take a minimum of 6 minutes to kill on her easiest mode, due to all the adds she spawns.

Leaving 14 mins to kill 3 mini-bosses, and over 9 packs of evil trash, of which at least 3 need to be mass CC'ed, lest they unleash their raid destroying aoe's upon the raid.

EDIT: Looks like they removed some trash from freya's room. This should actually be doable now.