Originally Posted by DarkSpirit

MoP needs to be cast on a monster, in the center of a mob that, hopefully, dies very slowly. Typically choose a boss or a healer. Then dont cast barbs on him or he would die fast, use fiends as minions and make use of him to kill the rest of the mobs fast. Unfortunately, heroes are not smart enough to make such decisions themselves so I would replace MoP on their bar with weaken armor.