A young and bright researcher working in the research labs of Peace Maintenance Brigade. Her project was to research energy sources in the dying continent. She possesses the special ability to memorize letters and pictures she has seen once and it helps make her an efficient researcher. Because of her timid personality, she is shy and poor at socializing. She likes to stay cooped up in her lab.
Her family was from Grangale and her father ruled Jaergen. They lived in a mansion in Jaergen, which was originally Neylern territory. Because of that, her father forbid her from playing with the other children here because her family was seen as outsiders and it wouldn't be safe. Fanille wasn't allowed outside of the mansion and she passed the time by reading books. Eventually, Elessa and her mother came to live in the mansion as live-in workers, and Fanille became friends with Elessa.
In her project to research energy, her theory involved fairies, so she wanted to find one. Krious and Elessa went with her to find one, and they befriended Korin by rescuing her from a monster. Korin agreed to help Fanille in her project, and Fanille successfully concluded that fairies naturally give off magical energy called mana.
When a group of attackers stole documents from the PMB during a peace conference, Fanille was assigned to go with Zeonsilt and Melvina to recover them. From then on they had to solve the conflicts occurring in the continent, and she learned to be more assertive little by little. As she was friends with Elessa for many years, it was a shock to her when Elessa betrayed the Peace Maintenance Brigade. It incited her to go on travel with Zeonsilt's group and find answers.
She was researching vital energy but scrapped it because it involved human lives. However, her research was continued secretly by the PMB under Isaac's orders. When it was found out that because of Zeonsilt's Zero Cell operation he had to intake vital energy in order to survive, Fanille felt terribly guilty for it. She suffered emotionally and vowed to find a cure for his body.
Merklich came from the outside continent and gave her a Pollumine seed, which Fanille found to be a lead in curing Zeonsilt's body. After experimenting with it and modifying it, she requested Merklich to take her to the outside continent where technology and medicine were more advanced. She was taken to the Lennox research facility, and together with a researcher there they produced a plan to cure the Zero Cell. Her experiment was successful in exterminating the Screaper cells from Zeonsilt's body and curing him.