Choose an element to which you already have applied the Elemental Focus feat. Your spells are remarkably potent, breaking through elemental resistance more readily than normal.
Prerequisite: Elemental Penetration.
Spells of the element you select are harder to resist. Any elemental resistance on a creature is considered 2 less when determining damage from a spell of the element you select, but is considered 2 more with spells from its opposing element. This bonus and penalty stacks with the one from Elemental Penetration.
Special: You can gain this feat multiple times. Its effects do not stack. Each time you take this feat, it applies to a new element type to which you have already applied the Elemental Penetration feat. This stacks with the Spell Penetration feat.