Elemental Equilibrium

You have mastered the art of elemental magic in the following schools: Fire, Cold, Lightning.

As a result your spell attacks from these elements inflict elemental exposure to the OTHER elements upon hitting a target. 
The target is exposed until the end of the casters next turn.

E.g
Fire spell = Cold/Lightning exposure.
Cold spell = Fire/Lightning exposure.
Lightning spell = Cold/Fire exposure.

Elemental Exposure causes the creature to take 25% increased damage from the elements they are exposed to.