Ipna was the first being created by the mother godess Thiol. He grew bored, and wanted a companion. Thiol gave him a female companion and made her perfect in every single way possible, almost an exact being as Thiol herself, and called her Nuil. Unfortunately for Ipna, she was just too perfect and grew bored of him and created the underworld where she settled.
But the second female Thiol created was not as perfect and she and Ipna had many children - called the Ipnya accordingly.