Frost backlash

Frost backlash is a fairly complex spell learned by swordmage initiates, particularly those of the shielding style of arcane swordplay. Unlike most spells, frost backlash can be cast instantaneously, and is used to transform the magical warding projected by all swordmages into frigid ice, which explodes out from the swordmage's weapon when they are injured by a nearby enemy. Even if the spell misses its target, the wave of cold energy still injures the attacker, making frost backlash an effective form of retaliation. Frost backlash is fairly difficult to cast and, as such, can only be used once per day.