Some type of Aether crystal/catalyst was sealed in Dalamund by the advanced civilization. The crystal allowed them to harness advanced technology, but it reacted in strange ways when exposed to the natural Aether. It has such a strong influence it goes Primals to go mad. The crystal eventually brings about an Umbral Era before it was sent into the sky. When it makes contact with Erozea, it will cause the natural aether to go haywire again causing mutations in the land, surrounding areas, and its people.