You're tired. You've been slaying the denizens of Icecrown Citadel for hours, you've spent your entire week clearing the daily heroics for your valuable Emblems of Frost, and you can't remember the last time you left Dalaran when you weren't en route to a raid. Your work has not been in vain, and you probably have some stiff new leather armor and maybe a plastic-wrapped weapon or two to show for it.
Your new armor is too tight, it is stifling and you must be nimble. If your weapons are too mint, they won't fit in your hands, and they will throw off your balance. With such little time left at level 80, we don't have the luxury of underperforming. How can you make your armor flexible to allow you to avoid enemy attacks? How can you mold your weapon to become an extension of your own arm? And how can you vent the pent up stress of mindlessly spamming Fan of Knives in heroics for hours on end? Luckily, there's a magic element that will solve all three of these problems: innocent blood.