Board Thread:Speculation House/@comment-27144409-20160720154947/@comment-4010415-20160802234253

Sentry 616 wrote: Well we have seen people use Dust on its own, but this level hasn't been seen yet, although if the information that the Maidens were added int after Volume 2 ended is correct, this may have been planned as Cinder's special power source.

That could be a(nother) reason. I'm pretty sure they intended for the power source to be that she infused her dress with Dust. After all,

1. The designs on her dress glowed when she used Dust.

2. We have this quote from Ironwood about Ruby saying that Cinder's clothes lit up: "Embedding Dust into clothing is an age-old technique. It could have been anyone."