Who is The Twins from The Way to Rainy Mountain and what is their importance?

The Twins begin as one boy. The boy is a child of the sun. There is also a woman by the sun into the sky. The boy’s mother died so he was raised by a spider known simply as Grandmother. The boy possessed a ring which Grandmother warned was dangerous when played with. The boy tossed his ring in the air which cut the boy in two hence the “twins”.