So... it's probably nothing, but reading about Ethniu's dad, Balor, on Wikipedia, I came across a character named Mac Kineely.
The story is that Balor stole Mac's magic cow of plenty. There was a prophecy that Mac couldn't get the cow back while Balor was alive, but that Balor could only be killed by his grandson. In order to fulfill the prophecy and get his magic cow back, Mac is transported by one of the fairy folk to the tower where Balor was keeping his daughter sequestered (to prevent a grandchild and the fulfillment of the prophecy). Mac seduces the daughter and gets her pregnant. The grandson kills Balor and Mac gets his cow back.
The daughter's name: Ethniu.
Could Mac Kineely be Dresden's favorite bartender, MacAnally?