In the chain quest for Shadowmourne, the quest A Feast of Souls requires you to kill 1000 mobs in ICC. Well as you may know the new weeklies in ICC just came out yesterday and there's a nice little trick on one of them to keep getting unintentional kills!
First step:
Deprogramming. Make sure your ICC raid ID has this weekly. This requires you to keep a certain named mob alive throughout the fight to complete. You may wipe and reset the fight if you fail at this.
Second step:
With Shadow's Edge, and while on the quest, KILL the named mob! This is the only mob from the side spawns on the Lady Deathwhisper fight that can actually receive the debuff for Shadow's Edge to consume its' soul.
Third step:
Have a warlock set up a teleport outside Lady Deathwhispers door. After you kill the named mob, have the warlock pull aggro on one of the other mobs and teleport out. This will reset the fight without a costly wipe. The fight can be repeated as many times as you want!
We were able to do this 25 times in about an hour, so that means 25 kills toward the quest closer to 1000. Enjoy!