Just be the right light level for it, shoot three eyes for the max damage, and go to town on the ogre. My sniper was hitting for 50k per shot at the time, and the ogre was down within a minute. The others for the most part were killing the mobs, and when the ogre was dead, I was basically the only one who even needed to do damage to the wizard with a 290+ sword. We had about a minute and fifteen seconds left when we finished.