Alia began her career as a simple researcher in Reploid engineering. She and her colleague Gate were ahead of their time in their research on Reploids, though she contends that Gate was always a better programmer than she was. However, Gate's inability to follow the rules made him a social outcast, and his creations were systematically destroyed, sometimes even with the assistance of Alia herself. She soon mastered all programming languages, and was chosen on these merits to be a spotter for the Hunters.
In Mega Man X5, Alia then served as the Hunters' spotter during the Sigma Virus outbreak, while simultaneously lending her technical talents to the cause by uploading and letting X utilize his two new armors, the Falcon and Gaea armor. She supported the Hunters throughout the ordeal until it was resolved.
In Mega Man X6, she spotted X and Zero as they dealt with the Nightmares, and her past with Gate came back to haunt her. Though feeling guilty throughout the happenings, she assisted the Hunters in bringing Gate to justice. When Gate was defeated, though, X brought his remains to Alia, and she said she would do her best to repair him, although it is unknown if she ever succeeded or not.
As the Earth Recovery proceeded, Alia continued to act as a Hunter navigator. Her skills were brought to good use when Axl escaped from the Red Alert Syndicate, a new hunter organization that had risen to power. With X having retired from the Hunters, he assisted Alia with her work at the base. During the crisis, Alia continued to guide Zero and Axl - and X, once he decided that he needed to help out - on their missions, eventually helping them locate Red Alert's base.
In Mega Man X8, Alia continued her spotter position, assisted by two new navigators (Layer and Pallette). Working in tandem, she assists in the discovery of the new generation chips and Sigma's plot. Beating Mega Man X8 once while selecting Alia as their Navigator the most will allow the player to purchase her as a selectable character for a second playthrough. The special Chip needed to unlock her costs 40,000 Metals. Alia is similar to X in terms of controls.