the sound of the wind, to soar
翏 centers on the sound of the wind and the motion of soaring through the air. The two given meanings connect through the idea of wind: the sound it makes and the way it lifts things upward.
翏 likely combines 羽 (feathers/wings) with a phonetic element 㐱, suggesting the sound of wind through feathers or the act of soaring. The exact historical development is uncertain.
Feathers 羽 on top of a shape that looks like wind lines 㐱: imagine wind rushing through feathers, making a whistling sound and lifting the bird to soar.
For リュウ, picture a strong wind making a long, drawn-out 'ryuuuu' sound as it blows through the feathers: ryuu -> リュウ.