What is the relation between Cethlenn (Old Irish) and the king of named Fomorians who is a interpreted as a god?
Cethlenn: In Irish mythology, Cethlenn (Old Irish), Cethleann (Modern Irish, or Cethlenn of the Crooked Teeth) was the wife of Balor of the Fomorians and, by him, the mother of Ethniu. Balor: In Irish mythology, Balor (modern spelling: Balar) was king of named Fomorians, a group of supernatural beings. Balor:  He has been interpreted as a god or personification of drought and blight.
wife