Improved Natural Spell Specialization
Natural Spell Specialization, ability to cast fifth level Druid or Cradled spells, or ability to cast fifth level spells and access to a domain available to druids.
This feat can be taken only once.
You cast spells in your area of specialization at +4 caster levels. Add +2 to the saving throw DC of all spells you cast in your area. But you cast all spells outside your area at -2 caster levels. If you are multiclassed, the feat applies to all spells you cast.