In the future, a majority of humanity's technological advances have been lost. Our kind turn to the natural kings of the skies to fight their airborne battles.
A small, shallow ocean planet in an unnotable corner of the solar system. Villages tend to center around aquatic-adapted ways of life, such as boating and fishing.
Humanity is long gone, leaving overgrown ruins reclaimed by Mother Nature. As the remaining plants and critters develop, they not only grow in size, but in sentience, alongside their peers.