This is my first post guys so please be nice im just trying to contribute =P hope this isnt posted before (although i checked) and that it will work for you.
You need two ppl for this. One of them is mage (i'll explain l8er y it may work with other classes)
Mage casts Polymorph on mob Warlock or Priest cast fear and Mage casts Polymorph again tadaa mob wont attack and you of course can
Note that instead of fearing the mobs i tried blinding them with a rogue and it workedso it may work with some other spells. Tested on Ascent 2.2-TRUNK r2287/Release-Win32-X86
EDIT: Not working on live servers. Moving to Emu Discussion due to lack of [Emu] before thread title.