During a recent run in Wanderer's Palace, I, the tank, went down after an Everyone's grudge. The Black Mage then began kiting King Tonberry around the room in a circle long enough for my weakness to wear off. King Tonberry was attempting to use Everyone's Grudge on the black mage, but because he kept moving wouldn't use it until he came to a stop. During this we were able to damage the boss, without triggering any more tonberry spawns, and without Everyone's grudge activating. Any action on the enemies' side was sufficiently stunted for a period of time, allowing us to take quite a large chunk out of KT's hp without incurring any damage ourselves.