Board Thread:Episode Discussion/@comment-410526-20160109160106/@comment-3257939-20160109212809

BenRG wrote: I'm pretty sure that it's been shown fairly explicitly (especially in the fight with Yang) that Mercury's semblance is ice generation and manipulation. Not explicitly. Much like with Cinder's ability, we don't know what about it is her Semblance, Dust or Maiden power. We can make a good guess but it's not obvious enough to be given for granted.

Plus Ice is solid. What Mercury shoots is gases.