Do not mez the adds. Don't even bother touching them. Take 1 character and pick up the ground spawn that pops during the fight. This gives you a single charge item that casts an aura that pulls all the adds into it. It's a free-target spell, so you can drop it anywhere you like, just make sure to drop it far enough away from your group. You don't need roots or mez to do this fight.
Exactly what I do. I pause my wizzie then pick up the item, do free target ring and unpause him. Once I figured that out it came from being frustratingly hard to ridiculously easy.



