-Momma... what should we do about the Other half?
-It's only a tale little one. You don't have to take it so literal...
This is the origin myth told by the religion of the people living in The Bottom of the World
In the beginning, there was only space. Then the Goddess hatched from out the top of the egg.
The goddess looked around at the space around her and found that she was not happy. She created the earth inside of the egg that she had hatched from. The earth was wast and deep. When she was finished creating flora she created fauna. She filled the deepness of her world with diversity. But when she reached the surface of her earth she was out of ideas and reused a couple of them when she created the surface flora and fauna.
When she finished her creation she took her first steps on the surface of her creation. She looked around and saw that what she had created was good. She spent time with the fauna of her creations until she decided to create creatures in her own image. She created the people from her horns, her hair, her scales, and her claws and saw that they were good. She spent time with her new creations but she was still lonely.
The Goddess took half her heart and created her opposite.
The two of them were happy for a while, watching the creations of the Goddess prosper. But the Goddess's other half grew bitter. With her, he was just another of her creations. He wanted to be his own person.
The Other half started whispering to her creation when her back was turned. He told them that everything that was different from themselves was wrong. He spread fear. He created new diseases and spread them among all the creatures. The Goddess didn’t know what had happened to her creation. It had become tainted. Her other half comforted her and said that they could wipe the world clean and create another one. A better one, together.
One of the people that the Goddess had created heard their conversation and had seen what the other half had done. They planned to tell the Goddess when the other half wasn’t looking. The Other half had heard their plan and sent a large creature after them. The creature chased the people down below the surface where the Goddess couldn’t hear them and the Other half couldn't hurt them.