Your natural knack for illusion allows you to maintain at least one illusion spell with little effort.
Benefit: You can maintain concentration on one spell of the illusion school as a swift action. This has no effect on spells of other schools or on illusion spells with durations that don’t depend on your active concentration. While you may only maintain one spell as a swift action, you may take your move and standard actions to maintain other spells normally, if you wish.
Normal: Concentrating to maintain a spell is a standard action that does not provoke attacks of opportunity.