Board Thread:Off Topic/@comment-24993958-20160711184711/@comment-25936766-20160903014825

RayStrikeAbius wrote: and the Semblance here is generating light, not storing it. That line reminds me of Excalibur and Excalibur Galatine from the Nasuverse. The former absorbs the light radiated from the Earth, while the latter reflects the rays of the sun.

You could do something like a combination of a Black hole and a White hole. Absorbs light and releases it later.