Psionic Complement [Multiclass Encounter]
Prerequisite: 4th level, any class-specific multiclass feat for a class that has the Psionic Augmentation class feature, Psionic Augmentation class feature
Benefit: You can swap one of your augmentable at-will attack powers for an augmentable at-will attack power of the same level or lower from the class you multiclassed into. You can use that power once per encounter.
Published in Player's Handbook 3, page(s) 194.