Board Thread:Speculation House/@comment-6490434-20130410061505/@comment-24198837-20150416201237

Weiss is the only character we've seen using ice (right?) so maybe Myrtenaster has some sort of way to focus it.

Alternatively, hasn't her use of ice dust been shown in conjunction with her Semblance every time we've seen ice-dust pop up? The only time it's not directly shown (I believe) was when she pinned the Nevermore to the cliff in V1.

So maybe it's something to do with a combination of her Semblance and the dust?

It would make no sense for Water and Ice to be different dust types.