Cyrgon was the god of the Cyrgai. He was first introduced in Domes of Fire, in references from Zalasta and Krager and during a fight between the Church Knights and Cyrgai (though in the latter case, he was disguised as the Troll God of Kill, Ghworg). He is properly introduced in The Shining Ones, when Aphrael and the newly-freed Troll Gods work together to break his disguise. At this point, he becomes the main antagonist against the group until he is usurped by Klæl in The Hidden City.
Cyrgon is generally viewed and depicted as a bullying, power hungry idiot. This is evidenced by his fierce warlike behavior and his hatred of innovation and knowledge, a trait he passed on to his children. It is also shown by his evident childishness, as he declares war on all races indiscriminately unless it suits his purposes to do otherwise and is shown to throw "tantrums" when he loses in battle. However, Sparhawk eventually comes to the realization that Cyrgon may not, in fact, be stupid, but merely an archconservative; thus, he is inherently fearful of change and the uncertainty it can bring, and so cannot react easily to new situations, giving him the appearance of stupidity.
Cyrgon's true appearance can only be speculated on. For much of The Tamuli, he assumed the form of Ghworg; immediately after this disguise fails, however, he denatures into "an amorphous blob of light", which, given his pain and lack of concentration, would suggest that this is or is at least close to his true form (and reveals a similarity between him and Edaemus of the Delphae). Most of the rest of the time, he assumed the form of a living, mobile, and shape-shifting golden flame. He claimed to be too proud to assume a human form, though Aphrael speculated that he was too unskilled in such a transformation to do it properly, and so shunned such a shape out of caution and/or embarassment.
Cyrgon was killed by Sparhawk when the two served as stand-ins for Klæl and Bhelliom, respectively, and Sparhawk ran him through his chest.