Demi-Nui was created by the Great Beings 10000 years after the success of Mata Nui. Demi Nui was made as to be a second Mata Nui with a similar design plan, along with a few modifications. The process was never completed. This was because of a virus that was killing off most of the life forms created for the planet. The Great Beings then abandoned Demi Nui for more favourable projects. It was then taken over by Olcara, a makuta who came from Mata Nui after being exiled. With his help the matoran survived and were modified, along with the other Rahi into vicious beasts, such as the Mator-Rahi.