The Keens are amalgamations created from the energy of "Aether" and minerals of the Earth. The Keens' bodies are surrounded by the most durable metals, giving them an indestructible body. However, their survival depends on the transformative power of the "Aether." If unable to maintain energy for themselves, the Keen will have to receive a tragic end to become inanimate blocks of metal. Therefore, the Keens live in the harshest lands, with abundant energy sources, such as majestic volcanoes or rivers that continuously emit heat. Existing in these habitats, it seems that the Keen rarely encounter other races on The Earth.