ok so we just had a buged storm wizard but we managed to kill him, it took us about 20 mins of messing around and we discoverd that there is one spot he could be hit and only by one person in the party
The spot was only if you are standing on the teleporter witch we will call six o'clock and you could only hit him at the four o'clock position, personaly i nor anyone else appart from the human could do it, so while im not 100% sure i think elevation/hight has something to do with it because as asura i could not hit him.
Needs more experimentation but hope this infolhelps some of you.