The Hollow

The Hollow are people who live in the cave systems of the Rucsui Mountiains. They rarely go out due to the fridge climate and know little of the outside world. They entered the caves long before written records and have few have left them after. They are unaware that they live in the kingdom of Pacellum or the fact that the kingdom exists. They're unaware of the Red King's reign or the descent of the six gods. They know of the gods and live in fear of the Shutch, but they know him by a different name, The Shadow Eater. 
They harvest The Shadow Flower and grow other vegetation in caves as most plants on the mountain require little to no light to grow and occasionally go out to hunt, but only as a coming of age ritual. 
The ritual is done once in a person's life and is when they are ready to face the Shadow Eater. They must hunt an animal without having their shadow eaten. The Hollow believe that their shadows are tied to their souls and if their shadow of the person is missing, they are called Shadowless and used as a sacrifice to the Shadow Eater to receive more food. 
While the Shadow Eater is something to be feared, the reason they receive food is because The Shadow Flower is a flower attracted to decaying bodies and the area the person is placed is a highly fertile place for the flowers, so more would appear than would in other areas on the mountain. 
The Hollow do no trade and have little need for arts since they live mostly in darkness. Because of the lack of light, they express themselves in sound. They have a rich culture in music and are always exploring to develop new sounds with the materials around them. They also use sound to navigate the caves and are the only people who still speak Hanasprochen (although it has adapted to fit the people's needs so it is not the exact same as what the people in Pacellum know. Though if they were to meet, they would still be able to communicate moderately well)