Choose a school of magic, such as illusion. Your spells of that school are more potent than normal.
General
Augment Summoning, Energy Gestalt, Energy Abjuration,
Add +1 to the Difficulty Class for all saving throws against spells from the school of magic you select.
You can gain this feat multiple times. Its effects do not stack. Each time you take the feat, it applies to a new school of magic.