Player Phase Kana Breath?

i'd prefer light breath because then she can run galeforce as well and then she'd be quite a beast

I'd reckon that light breathe is the better player phase weapon, since it's the only one of the two that directly enhances your offensive spread. Dark breathe is better as an enemy phase since it only affects attack and speed, so unless you want to run heavy blade along with a dancer, light breathe is probably your go to. Of course light breathe can run heavy blade too, not to mention you can pretty much do the same thing as a refined Dark Breathe by slapping Speed Smoke as a C-slot and attack smoke as your Sacred Seal.