|Circle Universe character character|
|Magic||Glass magic and lightning magic|
|Parents||affluent Namornese glass makers|
Kethlun Warder, or Keth, is from Dancruan in Namorn. He is from a prominent glass family, and while in Namorn he became a very talented glassblower. He earned himself glowing praise from his family, and enjoyed it. One day, while walking along the Syth, he was struck by lightning. While most people would have died, he survived. However, his glass prowess did not. He ruined everything he made, and his family sent him away as a journeyman, so that they would not have to deal with him anymore.
In 1039 KF, Keth is living in the city of Tharios, in the district known as Khapik. His cousin, the Tharian glassblower Antonou Tinas, let him rent his shop and use it for his workings. There was an understanding that Keth would pay him back, as Antonou was not a rich man. During his work, his glass got out of control and he accidentally created the glass dragon Chime. Trisana Chandler watched this all, angrily, and accused Keth of not using proper wards, as he managed to draw spells from all the neighboring shops and street into his working. He got angry and frustrated, and tried to destroy the glass dragon. Tris scolded him, saying that once a mage has made a living thing, then they must treat it as such. He doesn't listen, and she uses lightning to stop him. She also takes Chime.
He realizes that if he has glass magic, he should find a teacher so that he could learn to control it. He goes to the Mages' Society and gives them a glass ball shrouded in lightning. They say that if he is a lightning-mage as well as a glass-mage, then there is nothing that they can do for him. Niklaren Goldeye overhears this, and offers Keth a teacher, as he just happens to know a very accomplished lightning-mage in the area. When Keth sees Tris again at Jumshida Dawnspeaker's house, he is very adamant that Tris would not make a good teacher for him. But they manage to talk him around. When Niko and Jumshida Dawnspeaker go off to do important mage work, he and Tris talk about magic at Dawnspeaker's home. Then the arurim, or police force, come to the house. Demakos Nomasdina accuses Keth of being the Ghost and killing the yaskedasi. Keth protests, but is taken away. Tris goes with them. Nomasdina brings them to the scene of the crime first, and Keth, recognizing the murdered yaskedasu, is shocked. Then, they are brought to the Fifth District arurimat to be questioned by Nomasdina. When the arurim dhaskoi tried to use truth spells on him, Keth accidentally calls up lightning. Since Keth fights the other mage's power, Nomasdina starts to go for the torturers. This frightens Keth and he starts sobbing. Tris stops Dema, saying he should be ashamed of himself and that he should wait for a truthsayer - her teacher Niklaren Goldeye, to come. She raises a protective shield around Keth so that Nomasdina can't torture him. Goldeye and Dawnspeaker come and prove him innocent. They take him back to the house.
Keth doesn't wish to make magical glass scrying balls in order to see the killer at first. It is only when Yali, a love interest of Keth's, is killed by the Ghost, that he pulls himself together and makes them. He hurries though, as he is now much more attached to this project than before, and makes a lot of mistakes. Tris also moves in with him at Ferouze's house in order to help him with his magic, and to look after Glakisa Irakory - a young girl who was orphaned by the Ghost. It also turns out that she is an academic mage.
Finally, one of his crystal balls does show the Ghost's next intended victim - Tris. Niko arrives in a panic, and they hurry to track down Tris and the Ghost. Keth urges Tris to kill the Ghost - a prathmun - as he deserves to die for killing Yali and the other yaskedasi. She doesn't kill him though, and leaves him for the law.
Keth later offers to teach Tris glassmaking, and she accepts gladly. He laughs, planning to torture her (figuratively) exactly as she tortured him with her teachings.
He is mentioned again in 1043 KF when the Tris and her foster-siblings go to Namorn. He is mentioned by Berenene dor Ocmore, when she remarks that Keth had never mentioned that he would be capable of making Chime. The empress does not believe Keth is actually capable.