I've been playing with this idea of gathering magic from reflected light for a few days, but I hadn't figured out how to use it until today. Here is...
Juliet Hayes can absorb reflected light--moonlight, the sun on a lake, sparkling jewels--and turn it into magic. With that magic she can make herself reflect anyone around her--not their physical appearance, but their internal selves: skills, personalities, fears. The brighter the reflected light, the stronger the effect.
Juliet uses this power in the service of a secret organization called The SPIRE, doing whatever assignments come her way. But when she comes across a file she's not meant to see, she learns of another Juliet, one whose attributes are entirely identical to her own.
Now she's left wondering: who was she before she became Juliet Hayes? And why did she use so much power that she made herself forget her own name?