You have enhanced your radiances to their maximum potential.
Prerequisites: Illumination Bonus +3, ability to emanate radiances
Benefits: Your radiances have all of their variable effects maximised.
What radiances would this apply to?
Silly me! You're right, that wouldn't do anything at all! I just got caught up in designing feats that I forget that radiances aren't variable (though my earliest version had some of them variable). I'll get rid of this and modify Empower Radiance appropriately.