Here is a glitch I found playing the level were you have to defeat the five generals individually. I figured this out with my mage, but I'm sure it will work with any ranged character.
Once you clear the four rooms and you've broken the dark crystals and your about to use the teleporter to fight a general, step into the teleport and watch the general say his final words before you fight. Once the fight begins (the conversation is over) DO NOT MOVE! use your range attack (I've only done it with my staff) and he will come to you but not attack. At this point, I killed him in about 7 seconds spamming meteor. As long as you never move, the general will not attack while you attack him. Only one out of the five generals attacked me but it was possible I twitched the joystick, he was 75% down anyways.
Would be great to see if this worked with 4 people. If it did people could easily do this to farm the generals for gold items :)