“Another belief held that Shu and Tefnut were created by Atum having sexual intercourse with a goddess, referred to as Iusaaset (also spelt Juesaes, Ausaas, Iusas, and Jusas, and in Greek as Saosis), meaning the great one who comes forth. She was described as his shadow or his hand.”
You guys. You know that shadow we all know and love? The one that always appeared before the other Yuugi was about to kick some ass in Season 0?
That’s his wife.
(information from the Wikipedia article)