WoWDB

Somehow, despite having a 1 second cooldown, mine likes to periodically go on cooldown for 5+ minutes (I've had it in my bag for awhile; too lazy to do the quest and a couple times has been on cooldown when I've gone to).  Some of the things it shares a cooldown with must have long cooldowns, which makes no sense BUT WHATEVER.

Damage taken will break this buff, so make sure you clear out the imps if you go to do the quest.