Hi,
I've been a long time reader, but today I finally found something I couldn't find anywhere else, yet. In Act 3 in bunkers and the keep, there are Iron Gates that cannot be destroyed, but opened by clicking them. Today, I was able to just walk through it on one side avoiding to open the gate. At first I thought it was a lag and I was even able to reproduce it. I am NOT sure thought if it works on other Iron gates aswell or if it's specific to gates in this angle/location.
Using that, you're able to kite champion packs to that point and kill them easy by shooting through the gate! This only works with spells that pierce through groups of mobs like nether tentacles. Witch Doctors like me have to use WoZ and Grasp of the Dead.