Kayal

Fetchlings, who call themselves Kayal, are descendants of the ancient Azlanti. After the fall of the Azlanti Empire, a small group of survivors sought divine help to escape the destruction. Their prayers were answered not by the major gods, but by a forsaken deity known as The Widow, a minor goddess associated with shadow and loss.

The Widow created a portal to the Netherworld -- the plane of shadow—offering the survivors refuge. Isolated in this foreign realm, the Azlanti who entered the Netherworld began to change over generations. The plane's influence altered their bodies and minds, adapting them to its low light, shifting terrain, and eerie stillness.

These descendants became the Kayal: a people adapted to life in the shadows. Their skin, eyes, and senses evolved to suit the dim realm, and their culture diverged from their Azlanti roots. While they maintain some record of their origins, the Kayal are now a distinct people with their own traditions, shaped by centuries of life in the Netherworld and the guidance of the Widow.

Most modern-day humans can trace at least part of their Ancestry to the Azlanti. They were very similar to humans, and intermingled a lot.

It should be noted that the Azlanti are part of the wider world, and not something specific to the Frontier. All that needs to be known was it was an advanced society of humanoid people that was destroyed in ancient history.