Tirandys was the son of Daron, of the of Randir, and Periel, a Knorth lady. Periel was also the mother of Gerridon and Jamethiel Dream-Weaver by Cethron. Thus, Tirandys was half-brother to Gerridon. He had a full brother, Terribend, and another Randir half-brother, Keral.
When Gerridon fell, Tirandys followed him, knowingly damning himself, out of a mixture of loyalty to his half-brother and love for his half-sister. He followed Gerridon into Perimal Darkling and became a Changer, which gave him long life.
Three thousand years later, Gerridon gave the seven-year old Jame into Tirandys' care, instructing him to teach the young girl the Senethar just as he had her mother, Jamethiel Dream-Weaver, so that she might in time replace the Dream-Weaver in her task of reaping souls for Gerridon's immortality. While Tirandys's honor would not permit him to disobey Gerridon's orders, he instead carried them out perhaps better than Gerridon thought possible; as well as the Senethar, he taught his young charge honor and strength of purpose, so that she might do the right thing when the time came. He also did not interfere when someone—presumably Terribend—taught Jame to read and speak Master runes, and gave her a knife on the night in question. His machinations lead to Jame's flight from the Master's House and the loss of the Master's left hand.
Tirandys was given the task of eliminating and replacing Torisen during the Battle of the Cataracts. He first took the place of Prince Odalian of Karkinaroth to get close to Torisen, and suggested that Karkinaroth become a subject-ally of the Kencyrath. He wished, he said, to go through with a symbolic blood-binding to cement the oath, in private. He and Torisen went off alone to perform the rite, in which Tirandys would consume Torisen's blood and thus gain the ability to mimic his appearance. However, unknown to both of them, Torisen is a blood-binder; the combination of the two warring bloods would likely have been fatal, and certainly induced bone-breaking convulsions and agony. Tirandys took the Ivory Knife from Jame's boot and used it on himself after saving both Jame and Tori from being swept away in the storm caused by Jamethiel Dream-Weaver's death. Depite the general revulsion of the Kencyrath toward changers, Jame loved Tirandys as a sort of father figure and repeatedly uses his memory as a way to decide what to do. She remembers him as the only person to have fully accepted and loved her despite knowing everything that she was, a position that no one else is capable of filling.
Tirandys was a Senethari, a master and teacher of the martial arts and associated spiritual dance of the Kencyr, and was the teacher of Jamethiel Dream-Weaver, for whom he developed a style of Senethar optimized to the physique of the Highborn woman. His style was classic and remembered enough that three thousand years later at Tentir, the randon recognized his style in Jame's movement. (This presented them with what they viewed as the ultimate unsolvable conundrum: who had taught a Highborn girl from an excellent bloodline to be the best unarmed fighter most of them had ever seen?)