Mage-slaying blade of the Limit Breaker
Against any creature that can cast arcane spells, this +1 magebane longsword becomes a +3 longsword. Furthermore, the weapon deals an extra 2d6 points of damage against targets capable of casting arcane spells.
Each limit breaker has a sword crafted for him or her that accommodates their unique fighting style. They are enchanted so as to be more affective against their main quarry, magicians.