You'll need two people. Go to Execution Grounds. On the right side, there are Huge Stairs. Go up there and stand left or right of the socket of the Stairs. Then one of you pulls a lot of mobs down the stairs. At the half of the stairs the mobs ran back slowly. Then the person on the socket of the stairs uses AOE or Arrows to attack them now he has the aggro of 10+ Mobs, but they cant attack him. I hope this help.