Trianna was a female human. She had "startling" blue eyes, black hair, as well as a "wry" mouth. She was considered attractive, proud and dignified. Around her arm she wore a golden Snake bracelet called Lorga. The "snake" could be awoken using magic and was an heirloom created to protect her family. Trianna was a member of Du Vrangr Gata, which she lead with Eragon. She worked with Arya and Eragon. Other members of Du Vrangr Gata come and go, leaving Trianna as the most mentioned.
Not much is known of Trianna's early life. She was born to a healer in Surda: this healer, her mother, taught her how to use magic. Eventually Trianna joined the Varden and became a member of Du Vrangr Gata. At some point, Trianna learned the art of sorcery, the ability to capture spirits and force them to carry out the practitioner's will. Trianna was known to have used this form of magic only on one occasion when she was with the Varden, but only after being ordered to by Ajihad.
It is unknown if Trianna fought at the Battle under Farthen Dûr, but shortly after the battle Trianna attempted to beguile Eragon, possibly hoping to use his influence for her own benefit.
She was introduced early in Eldest, wherein she first met Eragon and flirted with him, while at the same time trying to convince him to join Du Vrangr Gata – to which he politely declined. While Eragon seems attracted to her, Saphira is not at all amused and interrupts them, leading to an argument between Saphira and Eragon. Saphira tells him that since whoever Eragon associates with will be inevitably involved in her life, she insists it be someone she trusts: someone who cares for the Eragon the person, not Eragon the Rider.
Nasuada assigned Trianna with the task of hunting down and destroying the members of Black Hand and use magic to make lace to fund the war—the latter task she was not enthusiastic about. Trianna joined the Varden on the journey from Farthen Dûr to Surda. Once in Surda, Nasuada charged her with the task of making lace with magic, in a fund-raising effort, as well as enlisting the rest of Du Vrangr Gata to help the Varden with their magic. Trianna was not very pleased with the task, but agreed to do it nevertheless. Afterwards, Trianna helped to capture and inspect the mind of Drail, an agent of the Black Hand, who tried to kill Nasuada.
In "The Gift of Dragons", Eragon sings about the life of a man and a woman. The woman is mentioned has having "midnight blue" eyes, possibly referring to Trianna. Eragon also mentions Trianna in a conversation with Arya about spirits. Trianna was also amongst those present at Nasuada's Trial of the Long Knives.
Battle of the Burning PlainsEdit
Later, Nasuada placed Trianna in charge of the Varden's spellcasters for the Battle of the Burning Plains. Trianna temporarily and grudgingly yielded her position as leader of the Du Vrangr Gata to Eragon shortly before the Battle of the Burning Plains: while Trianna was suspicious of this and suggested that she has not carried out her duties worthily enough, Eragon used diplomacy to arrange a kind of sharing of authority between the two, making her the lieutenant of the Du Vrangr Gata. They both carried the shared authority into the events in Brisingr and following the battle, Trianna continued to serve on Du Vrangr Gata and weeks later took part in healing Roran's injuries when he was whipped for insubordination. It also seems whatever attraction she and Eragon had toward each other had mellowed.
Trianna was a person who was willing to place her own desires before the good of others. During her time as leader of Du Vrangr Gata she became accustomed to authority and did not wish to give it up: she viewed Eragon taking over the Du Vrangr Gata as a criticism of her leadership. She also believed that the Du Vrangr Gata served the Varden of their own free will and that therefore the leader of the Varden had little authority over them, thus showing her arrogance. Despite her apparent narcissism, she proved to be a loyal and competent magician, visibly by the fact that she often met perfection any task she was ordered, yet that often reluctant.