If you have been raiding 10-man Dragon Soul every week, Wrathion should be handing over the Fangs of the Fathers any day now. Even the second rogues in most 25-man groups will be collecting their last Elementium Gem Clusters shortly. For many rogues, these daggers are the first legendary weapons that they've ever acquired. When you receive them from Wrathion, it might feel a bit overwhelming. What do you do with these weapons? What will they do to you?
There is a quote that's been passed down from thief to thief, assassin to assassin, and rogue to rogue for generations: "If your blades are happy, you're happy." You want your weapons to work for you, and not the other way around. You can't starve your blades, trying to forcefully adjust their diet to tolerate Morchok's rocky hide or Hagara's snow cones. If you want to keep your blades happy, you have to feed them what they really want: player blood, and lots of it.