Board Thread:Speculation House/@comment-14138255-20151213162620/@comment-26463535-20151215000102

The match was over though because Mercury had 0 aura left. And aura is needed to use a semblance. And just because Cinder has fire powers doesn't mean she didn't have a Dust woven dress.

She's a sly one and doesn't reveal all her cards. The dress was a good cover for people to automatically assume the fire came from. The popcorn incident was small and wouldn't be that noticable in a crowded arena, if Mercury and Emerald don't know then they could come up with their own ideas about where it comes from, though mostly it was a way to hint at the fact she really did have control over fire.