|Laran||Alton Gift, telepathy|
|Spouse||Domenic Alton-Hastur (freemate)|
|Siblings||Geremy-Esteban Ardais (paternal half-brother), Valentine Ardais (paternal half-brother), many other unnamed paternal half-siblings|
|Children||Unborn child (by Domenic)|
|Novels||Traitor's Sun, The Alton Gift, The Children of Kings|
Illona Rider was a baby when she was found by the Travelers (singers and storytellers) in a town that was raided and burned down by bandits. Since the village was in the Ardias Domain it is very likely she is the nedestra daughter of Kennard-Dyan Ardais, upon meeting her he was shocked of her resemblence to Eduina MacGarret, a young woman he had a daliance with.
While she and Domenic Alton-Hastur were young they met during a Terranan plot to kill Mikhail Hastur and the rest of the Comyn Domain heads during the funeral of Regis Hastur. The two became fast friends and were students together at Neskaya Tower for a few years. It was there that Illona discovered she had incredible talent, she possessed the Alton Donas and went on to become Under-Keeper at Nevarsin Tower under Silvanna, who Lew Alton believed to be the missing daughter of Regis Hastur .
After a few years of separation when she and Domenic re-met they were drawn together as more than friends and soon became lovers, despite his vow of marriage to Alanna . He even proposed to Illona but she told him he must be true to his promise and she would rather be his lover and be independent to pursue a path within the Towers.
During this time a dreadful disease was spreading through the countryside which had people dying and flocking to Thendara for help. Illona and some of her Tower circle tried to heal a man at St. Valentines of the Snows but the man died; after some research she was sure it was a new flare up of Trailsmans disease. Accompanying Domenic and his grandfather Lew Alton to Thendara realize how wide spread the disease is, since it is Council season Illona and a contingent of Keepers are able to help find a cure for the disease.
Illona Rider is a very independent and calm young woman, wise beyond her years, who has taken her training as a leronis very seriously. She is described as having curly wiry red hair, gray-green eyes, a slight turned-up nose and a generous mouth.