The Weylan spent the two millennia following the last great war rebuilding their civilization. Arkadia was a binary system, and the other star had a gas torus in orbit thick enough breathe in. There is some speculation that it was created via an Albion experiment, but hard information was lost when the primary Arkadian planet was destroyed. The Weylan moved into the gas torus, and towed pieces of the old planet over to act as small planetoids they could live on. They’ve lived in the seemingly endless skies of Arkadia ever since. They’re wings make them uniquely adapted to the environment, and under normal circumstances they probably would have multiplied like rabbits in their new world. But that is one thing the Weylan can’t do. Have babies. They are born infertile.