Air and water speak different languages: one reasons what the other feels. There lies the challenge and the magic — water teaches air depth, and air gives words to what water can't name. Patience required on both sides.
One holds steady (fixed), the other flows (mutable): the fixed one gives the mutable roots, and the mutable teaches the fixed that changing isn't losing. Complementary — as long as neither caricatures the other as 'stubborn' or 'flaky'.