What are the Lunars (besides, you know badass shapeshifters who've earned the blessing of the witch-goddess Luna)? Lunars are divine apex predators. The theme of predation is already deeply rooted in them—there's a reason they need to consume their prey to take on their form, at least, at first—and it's reflected in their Charms. Whether it's dancing between shapes as you tear a Wyld Hunt to shreds, ruthlessly pursuing your political agenda in a court of scheming nobles, or hunting down the forbidden secrets of a god exiled to the borders of the world, you are on the hunt.
But, of course, just because Lunars are predators doesn't mean they're limited to violence and consumption. Lone wolves rarely thrive. A Lunar who wants to engage with a society, whether it's a dominion that she rules, a cult that worships her as a living god, or just some people she wants to help, is going to do so in the manner of a predator conferring its assistance to prey animals. She might become a sacred guardian, stalking the bounds of a city to rip out the throat of any devil or ghost that dares harm her flock. She might be a heartless predator that culls the herd of its weak to make it stronger, taking on a terrifying devil aspect to temper a society. She might be the raven who steals the secret of fire, returning to society bearing the gift of wisdom. I refer to this as their theme of Symbiosis.
Also, their badass shapeshifting asskickers chosen by the witch-goddess Luna. Can't forget that!