Ok before i explain i just have to say This spell doesnt work in pvp( but i had an idea that if someone taunts you that person HAS to attack that person for one round :D)
Ok Say your with your friend thats lets say Storm. Your ice most likely cause you got taunt. When you cast it on an enemy it generates threat onto them meaning they will be more likely to attack you. The more pips you have when you use it the more "Threat" you generate on your target. This is good for ice because they have more health/ defense. So your storm friend wont get hurt and you'll be taking the damage.