What kind of powers would a mage of breath have? Would a magical language of sorts fit the motif?

It may fit a Heir or Witch of Breath more than a Mage, given they are the Magician Classes who are more closely related to ‘spells’, but with the title of a Mage, and the close relationship of Know and Change, I don’t see why not!

Do remember a Mage’s prowess is mostly in Knowing, however, even being the more Active of the two Know Classes, and Adept at Miracles, Insight and Knowledge are their power’s forte. Which is not to say it has to be their forte or their own preferred thing to do- I mean have you seen Rose? She’s great with Needles and Magic Prowess.

As for powers in themselves, a knack for Leadership, leading to Freedom, liberating those or that which they want, as well as knowing the twists and turns of the plot, they’d be kind of a really interesting Prophet for sure. Also literally Knowing Wind, maybe they can predict the weather…? That’s sort of a power I wish I had.