I have an earth mage and water support and I freeze and tree bind the earth and wind guards then do the same for the fire and water next turn. But my fires are strong enough that I don't really need to do that. If you have an earth you can use tree bind to seal the guards. If you have a water freeze them and if you have sleep and the guards are lined up next to each other you can sleep them. Just play around with it and find a strategy that works for your character/characters ^^