Board Thread:Off Topic/@comment-24993958-20150311232923/@comment-10390252-20150415081941

To me, Weiss's Semblance is a pure physical force manifestion, probably electromagnetic or the metaphysical 'aura' energy (probably similar to the biogenic energy from Final Fantasy - The Spirits Within).

Weiss's semblance creates the ice-white glyphs which act as shields or platforms and whose position and alignment she can control. What she does with Myrtenaster is charge the electromagnetic field with various type of dust product energy. This integrates with the glyph to create an energised disc that has various properties depending on what type of Dust is used.

Weiss has also obviously taught herself quite a bit of Semblance manipulation given that she's been shown projecting discs over long distances and with considerable accuracy.