mana burn
A rather nasty way of dealing with a spell-casting opponent is to turn his mana boiling. This will cause the victim to suffer damage whenever it casts a spell, proportional to the ammount of mana used. Victims also do not gain the benefit of mana shield or phoenix stance. Note: Only a spell's base cost figures into the damage dealt. The extra mana used by spells like siva's sacrifice causes no damage.