Choose one school or descriptor of magic (acid, air, animal, arcane, calling, charm, cold, compulsion, creation, death, divine, earth, electricity, fear, figment, fire, force, glamer, healing, innate, language-dependent, light, mind-affecting, phantasm, plant, possession, shadow, shapechanging, sonic, summoning, water) to which you have already applied the Spell Specialisation feat. Your spells with this descriptor are more potent.
Prerequisite: Improved Spell Focus with one school that includes a spell with this descriptor, Spell Specialisation, magic power 15+.
Benefit: Your spell receives an additional +1 bonus to the save DC and an additional +2 bonus to defeat spell resistance.
Special: You can take this feat multiple times, but the effects do not stack. Each time you take this feat, it applies to a different subschool or descriptor of magic. In addition, each time you cast a spell that can benefit from this feat, it can only be affected once.